WO2024013217A1 - Cover for a substrate plate of an enzymatic synthesis apparatus - Google Patents

Abstract

The present invention relates to an enzymatic synthesis apparatus configured for the synthesis of biomolecules, comprising a support platform (18) having a receiving area configured to receive a substrate plate (16) on which ink drops containing synthesis reagents are disposed, the enzymatic synthesis apparatus comprising a cover (22) for covering the substrate plate (16), the cover (22) being equipped with reversible hooking means (40) for reversibly hooking to a frame (42) of a covering station of the enzymatic synthesis apparatus.

Description

DESCRIPTION

Title ^: Lid for substrate plate of an enzyme synthesis apparatus

The present invention relates to the field of devices for the enzymatic synthesis of biomolecules, and more particularly devices for the synthesis of oligonucleotides such as RNA and DNA by inkjet printing.

DNA and/or RNA polynucleotides are linear polymers of nucleotide monomers or analogues thereof that are capable of specifically binding to other oligonucleotides through a regular pattern of interactions between monomers. The size of polynucleotides generally varies from a few monomers, for example from 5 to 40 monomers when they are usually called "oligonucleotides", to several thousand monomers. Usually, polynucleotides include the four natural nucleotides, for example deoxyadenosine, deoxycytidine, deoxyguanosine, deoxythymidine for DNA or their ribose equivalents for RNA, linked by phosphodiester bonds; however, they may also include non-natural nucleotide analogues, for example modified bases, sugars or internucleoside linkages.

When an inkjet printing device is used in an apparatus for enzymatic synthesis of DNA and/or RNA, defined quantities of an enzyme solution can be delivered to precise locations on a substrate comprising DNA and/or RNA initiator fragments. The enzymatic solution, which contains synthesis reagents including enzymes, can for example be deposited on the substrate in the form of ink drops.

In order to optimize the progress of the enzymatic synthesis which results in the elongation of the initiator fragments, an incubation step in a humid environment of the substrate may be necessary. This incubation step in a humid environment aims in particular to limit the evaporation of the ink drops and to ensure that the enzyme has the necessary time to catalyze elongation. In order to control the humidity of the environment in which the substrate is located, it is known from the prior art to enclose the enzymatic synthesis apparatus in a housing to which a humidity control member is added. Such a solution, however, involves achieving a connection of the enzymatic synthesis apparatus to equipment external to the housing. It is also necessary to insulate components that could be adversely affected by humidity, for example printed circuit boards where humidity could cause short circuits or corrosion. Also, such a solution complicates access to the enzymatic synthesis apparatus, for example for maintenance operations, since access must be limited to easily control the humidity level. Finally, for a housing surrounding the entire enzymatic synthesis apparatus, volumes of wet fluid necessary for incubation are generally large.

Furthermore, the enzymatic synthesis process using an inkjet printing device involves steps other than ink deposition and incubation. Steps of deprotection of DNA or RNA fragments or washing are for example necessary at each elongation cycle, in order to ensure that the polynucleotides are formed according to the desired sequence, each of these steps involving the projection of a suitable liquid or the immersion of the substrate in this liquid. It is thus known to cyclically move the substrate and the fragments found there from a deprotection station to a station in which elongation is carried out then to a washing station. Each move is detrimental to the speed of the synthesis operation as a whole, and to its cost price.

The present invention fits into this context and thus has as its main object an enzymatic synthesis apparatus configured for the synthesis of biomolecules, comprising a support platform comprising a reception zone configured to receive a substrate plate on which drops are arranged ink containing synthesis reagents, the enzymatic synthesis apparatus comprising a cover intended to cover the substrate plate, the cover being equipped with means for reversibly attaching to a frame of a covering station of the synthesis reagent enzymatic synthesis. The enzymatic synthesis apparatus according to the invention allows the enzymatic synthesis of polynucleotides, for example fragments of interest or even complete biomolecules. The enzymatic apparatus includes several stations dedicated to different stages of such enzymatic synthesis, including a printing station comprising a printing device and a covering station. A substrate plate is movable between the different stations, that is to say it can be moved from one station to another, for example by computer control. This substrate plate can be moved via a support platform, which for this purpose comprises a reception area where the substrate plate can be deposited.

This substrate plate is where enzyme synthesis occurs. It is in fact carrying initiator fragments intended to undergo an elongation step, which is carried out thanks to the synthesis reagents contained in the ink drops. These synthesis reagents include enzymes, which require a humid environment to optimally catalyze the elongation step. This humid environment can be implemented via a cover which is placed, on the support platform, covering the substrate plate. Such an overlap allows an incubation stage to be carried out.

This cover comprises reversible attachment means to a frame of the covering station, which allows the cover to be detached from the frame to place it on the support platform covering the substrate plate and its attachment to the frame when the incubation stage is completed.

It is thus possible to embed different appropriate means to allow one or other of the stages of an enzymatic synthesis process, such as means making it possible to regulate ambient conditions favorable to the elongation of the fragments, or means allowing to guide an appropriate fluid.

According to one characteristic of the invention, the cover is configured to form with the support platform, when it is placed against this support platform, a fluid circulation conduit across which the substrate plate is placed. In this way, it is possible to leave the cover in position once it has been placed on the support platform and to carry out, without moving the support platform to change station within the enzymatic synthesis device, a deprotection operation. , by passing through the circulation conduit thus formed a deprotection solution containing specific reagents such as reducing agents or even enzymatic cleavage enzymes. It is also possible to leave the cover in position once it has been placed on the support platform and to carry out, without moving the support platform to change stations within the enzymatic synthesis device, a cleaning operation, by carrying out pass water or a cleaning solution into the circulation conduit thus formed. It is also possible to leave the cover in position once it has been placed on the support platform and to carry out, without moving the support platform to change station within the enzymatic synthesis device, a drying operation, by doing pass through the circulation duct thus forming a flow of hot air.

According to one characteristic, the cover is equipped with a means of humidifying the substrate plate. The present invention thus aims to overcome some of the disadvantages previously mentioned, by proposing targeted regulation of humidity to optimize the regulation of the humidity of the substrate plate, in particular during an incubation step.

Humidity is obtained through the humidification means integrated or connected to the cover. Thus, optimal humidity is achieved for the incubation step via a covering means which has reduced dimensions compared to the solutions of the prior art, this covering means being adapted to the dimensions of the substrate, and which thus makes it possible to limit the quantities of wet fluid required to ensure the desired humidity.

According to another characteristic of the invention, the humidification means comprises a fluid inlet and a fluid outlet, said inlet and said outlet being provided in the cover.

The humidification means thus makes it possible to convey fluid participating in humidification via the fluid inlet, and to evacuate it via the fluid outlet. These fluid inlets and outlets are provided in the lid; these are for example orifices arranged on the walls of this cover. Such orifices can advantageously be arranged at opposite ends of the cover, thus allowing the wet fluid to pass from one end of the cover to the other.

According to another characteristic of the invention, the humidification means comprises a reservoir configured to allow humidity to pass from the reservoir to the substrate plate.

Such a reservoir is configured to receive a saturated saline solution. The reservoir may in particular correspond to a housing for a cartridge of the saturated saline solution. Alternatively, this reservoir can be a compartment that can receive the solution via a syringe.

According to another characteristic of the invention, the reservoir is provided in the cover.

Thus, the reservoir corresponds to a release of material within the cover, which allows the storage of fluid in this cover. It is not necessary here that the tank be connected to the fluid inlet and outlet. Such an arrangement makes it possible to limit a quantity of fluid necessary for humidification, in comparison to a quantity of fluid necessary for the embodiments where the fluid passes through the cover from the inlet to the fluid outlet without being stored there. The reservoir can in particular be delimited by a low wall which retains the fluid within the reservoir, at a distance from the substrate plate, but which has an opening allowing the passage of humidity generated by the fluid.

According to an alternative characteristic of the invention, the tank is provided in the support platform and is connected to the inlet and outlet provided in the cover.

We understand here that according to this embodiment, the tank is no longer carried by the cover but by the support platform.

According to another characteristic of the invention, the reservoir is provided in the support platform and comprises means for communicating with the substrate plate. In such an embodiment, the positioning of the cover on the support platform can for example result in the lowering of pins which otherwise constitute a barrier between the reservoir and the substrate plate.

According to one characteristic of the invention, the cover comprises drying means, for example by supply ducts for blowing hot air.

According to one characteristic of the invention, the cover comprises means for supplying a cleaning liquid and/or means for supplying a fluid capable of carrying out the deprotection of the end of a DNA fragment or RNA.

According to another characteristic of the invention, the cover is equipped with a humidity sensor and/or a temperature sensor.

Such sensors, and in particular the humidity sensor, make it possible to implement humidity regulation operations according to the values recorded by this sensor, in order to ensure that a humidity level is conducive to the 'elongation.

According to another characteristic of the invention, the reversible hooking means are configured to cooperate with reversible hooking members of the frame of the recovery station.

In other words, the frame carries reversible hooking members which are the counterpart of the reversible hooking means carried by the cover. These reversible attachment members are, for example, magnets or ferrous metal inserts.

According to another characteristic of the invention, the reversible hooking means and/or the reversible hooking members comprise at least one electromagnet.

Such an electromagnet allows the cover to be reversibly attached to the frame of the recovery station, or on the contrary tends to push the cover away from the frame, when an electric current passes through it; we understand that hooking and unhooking are done by magnetic attraction/repulsion. Of such reversible attachment means can be implemented quickly as soon as the cover is facing the frame.

According to another characteristic of the invention, the reversible hooking means and/or the reversible hooking members comprise at least one permanent magnet.

In addition to the electromagnet, the reversible attachment means and/or the reversible attachment members may include a permanent magnet. The combination of these two types of magnets provides security in the event of electrical power outages which would deactivate the electromagnet, with the permanent magnet then ensuring the attachment alone. Such security makes it possible to prevent the lid from falling on the support platform in an untimely manner, particularly outside the incubation stage, or on the contrary that the lid remains permanently on the support platform and prevents the realization a subsequent step of printing the substrate plate.

According to another characteristic of the invention, the reversible hooking members comprise at least one magnet.

We understand that this magnet, which is therefore arranged on the frame of the recovery station, is intended to cooperate with the permanent magnet or the electromagnet constituting the reversible attachment means. As mentioned, the reversible hooking members can also include an electromagnet, which is configured to participate in unhooking the cover and push the cover away from the frame, towards the support platform of the substrate plate.

According to an alternative characteristic, the reversible attachment means comprise at least one suction member.

Such a suction member is an alternative to the electromagnets previously mentioned. This suction member is for example a suction cup which allows attachment by creating a vacuum.

According to one characteristic, the support platform comprises reversible fixing systems, the reversible fixing systems cooperating with reversible fixing instruments arranged on a lower wall of the cover facing the support platform.

This is a particular embodiment of the printing device according to the invention, in which it comprises, in addition to reversible fixing means and complementary reversible fixing members already mentioned and which allow the hooking and unhooking the cover on the frame of the covering station, reversible fixing elements which ensure the position of the cover on the support platform once the cover is removed from the frame. The solutions implemented for the cooperation of the reversible fixing means with the reversible fixing members, and for example magnets and/or vacuum members, can be applied in the same way to reversible fixing systems and instruments.

As a result of these different configurations, several embodiments can be implemented to attach and unhook the cover from the frame and position it on the support platform.

In a first case, the cover is fixed on the frame of the recovery station by the action of one or more electromagnets, configured to permanently retain the cover against the frame until current is injected into the electromagnets, which has the effect of pushing back the cover of the frame. This current is injected as the support platform passes under the cover station, so that the cover settles by gravity on the support platform.

In a second case, the cover is fixed on the frame of the covering station by the action of the reversible hooking means and the corresponding hooking members, such as permanent magnets or vacuum means. When the support platform passes under the cover station, one or more electromagnets present on the support platform and/or one more electromagnets present on an underside of the cover facing the support platform are activated to attract the cover towards the cover. support platform and allow the positioning of this cover covering the substrate plate. When the electromagnets are no longer powered, the cover automatically returns to its place on the frame of the covering station, at a distance from the substrate plate, if necessary by being returned to position by means forming a spring.

It is notable that in these different cases, the reversible hooking and fixing elements are configured so that, in the event of a power supply failure, the cover remains hooked, or returns to a hooked position, to the frame of the covering station , at a distance from the substrate plate, so that it can continue the enzymatic synthesis cycle and be moved, without the cover being present, to other stations.

According to one characteristic of the invention, the cover comprises a cavity sized to accommodate the substrate plate.

This cavity forms a recess within the cover so as to accommodate the substrate plate. Thus, it is possible to press the cover against the support platform without coming into contact with the substrate plate and therefore without risking interfering with the shape and arrangement of the ink drops.

According to another characteristic, the cavity extends from a wall of the cover opposite a wall of said cover carrying the reversible attachment means.

According to one characteristic, the humidification means is able to cooperate with the cavity.

Here we mean by “capable of cooperating with the cavity” that the humidification means participates in the humidification of the cavity. By way of non-limiting examples, the humidification means may consist of a chamber formed within the cover, on the periphery of the cavity, with a low wall helping to delimit both the cavity and the chamber, the chamber being filled with 'a fluid suitable for generating humidity, the wall being dimensioned to form an opening for the passage of humidity from the chamber to the cavity while maintaining the fluid within the chamber, at a distance from the plate substrate housed in the cavity. According to another characteristic, the support platform and/or the cover are equipped with keying means.

These keying means facilitate the positioning of the cover on the support platform, so that the substrate plate carried by this support platform is correctly received in the cavity of the cover.

According to one characteristic, the cover is made at least partly of a transparent material.

The use of a transparent material allows imaging operations to be performed on the substrate plate when it is covered by the cover.

According to another characteristic, the cover includes a heating element. Like the humidification means, the heating element can promote the incubation step, by heating the substrate plate to an optimal temperature for incubation, and/or by heating the fluid intended to produce the humidity previously mentioned. Such a temperature is for example between 30°C and 70°C. The heating element can also help prevent condensation from forming on the cover, which could interfere with imaging operations.

The invention further relates to a method of enzymatic synthesis by an enzymatic synthesis apparatus as mentioned above, comprising a first positioning step during which the support platform carrying the substrate plate is positioned, within a printing station, under a print head of the enzymatic synthesis apparatus so that the receiving zone of the substrate plate is positioned facing said print head, a printing step during in which ink drops containing synthesis reagents are deposited on the substrate plate, a second positioning step during which the support platform is positioned in the covering station facing the cover so that the substrate plate is positioned under the cover, and an unhooking step during which the cover is deposited on the support platform covering the substrate plate by a change of state of at least the reversible attachment means. The enzymatic synthesis method according to the invention therefore involves a first positioning step which makes it possible to place the support platform in a first position within a printing station, that is to say so that the substrate plate is facing the print head. The substrate plate is then ideally positioned for the printing step which results in a deposition of synthesis reagents on this substrate plate, via at least one of the projection nozzles forming the print head and which ejects ink containing these synthesis reagents. Once the printing step has been completed, the support platform is moved again during the second positioning step to take a second position, in which the supporting receiving area of the substrate plate is placed under the support frame. the recovery station, and more particularly with regard to the cover attached to this frame. An unhooking step then occurs, during which the cover is unhooked from the frame and is placed on the support platform covering the substrate plate. Such an unhooking step involves the reversible hooking means, which are activated or deactivated to allow such unhooking. The change of state of the reversible attachment means, when the support platform arrives in the covering station and the substrate plate is under the cover, makes it possible to move from a configuration where the cover is retained by the frame of the covering station has a configuration where the cover is deposited on top of the substrate plate.

Depending on the configuration of the reversible attachment means, they can be active or otherwise inactive when the cover is retained on the frame of the covering station. For example, the reversible attachment means can change state so that the cover is deposited by gravity on the support platform of the substrate plate or so that the cover is attracted by the platform support and/or pushed back by the frame. Without limiting the invention, these latter attraction/repulsion effects may in particular be due to an appropriate magnetic field or to a vacuum and positive pressure effect.

In each of these cases, after incubation, the changes in state of the reversible attachment means are carried out in the opposite direction, so that the cover is detaches from the support platform and can return to its original place, hooked against the frame of the recovery station.

According to one characteristic, the method comprises a humidification step occurring after the unhooking step, since the cover is positioned covering the substrate plate.

The humidification stage occurs when the cover covers the substrate plate, that is to say when the latter is housed in the cavity of the cover. This humidification step involves the humidification means, by means of which the substrate plate is humidified in order to prevent the drying of the ink drops containing the synthesis reagents placed on the substrate plate.

According to one characteristic of the invention, the method comprises a hanging step during which the cover is lifted and hung on the enzymatic synthesis apparatus.

Such an attachment step, or fixation step, is the opposite step of the unhooking step. It results in activation of the reversible attachment means, which allows the cover of the support platform to be lifted and attached to the frame of the covering station of the enzymatic synthesis apparatus.

According to another characteristic, at the end of the second positioning step, a distance between the support platform and the cover is less than two millimeters.

Such a distance makes it possible on the one hand to avoid oversizing of the reversible hooking means and on the other hand to limit the impact of the shock between the cover and the support platform when at least the reversible hooking means change state and that the cover covers the substrate plate.

According to another characteristic of the invention, between the unhooking step and the hooking step, the support platform is moved to an imaging station distinct from the printing station and the covering station .

After the unhooking step, that is to say once the cover is placed on top of the substrate plate, the support platform leaves the station recovery and is directed to one or more other stations of the enzymatic synthesis apparatus. The support platform can thus be taken to an imaging station where operations to verify the enzymatic synthesis are carried out.

According to another characteristic, at the end of the hanging step, the support platform is moved to a cleaning station separate from the printing station and the covering station.

Within this cleaning station, the substrate plate can be washed or rinsed. Moving the support platform to the cleaning station occurs after the cover has been removed from the support platform, when this washing or rinsing requires the substrate plate to be accessible.

Alternatively, the washing or rinsing operation can be carried out while the cover is placed on the support platform, covering the substrate plate. For this purpose, the cover may include means for circulating fluid, whether air or liquid, at a given temperature. The cover may also include means for circulating a fluid allowing the deprotection operation necessary for the enzymatic synthesis process.

According to one characteristic of the invention, after the unhooking step, a pump is actuated to circulate a fluid between the inlet and outlet of the cover.

The pump facilitates the circulation of fluid from one end of the cover to the other.

According to another characteristic, the pump is fluidly connected to the cleaning station.

Such an arrangement makes it possible to facilitate the management of fluids within the enzymatic synthesis apparatus.

According to one characteristic, after the unhooking step, the saturated saline solution diffuses into the lid. Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended drawings on the other hand. , on which ones :

[Fig. 1] illustrates, schematically, an enzymatic synthesis apparatus according to the invention comprising a printing device, in a perspective view?

[Fig. 2] illustrates, schematically, a printing station comprising the printing device of Figure 1, a single projection nozzle being made visible here;

[Fig. 3] illustrates, schematically in top view, a cover according to a first aspect of the invention configured within the enzymatic synthesis apparatus of Figure 1 to cover a substrate plate made visible in dotted lines;

[Fig. 4] illustrates, schematically, the first embodiment of the cover of Figure 3 in a side view;

[Fig. 5] illustrates, schematically, a second embodiment of the cover configured within the enzymatic synthesis apparatus of Figure 1 to cover a substrate plate, the cover here not being equipped with a window transparent closure;

[Fig. 6] illustrates, schematically, the second embodiment of the cover of Figure 5, in a side view, the cover here being equipped with a transparent closing window;

[Fig. 7] illustrates, schematically, a third embodiment of the cover configured within the enzymatic synthesis apparatus of Figure 1 to cover a substrate plate;

[Fig. 8] illustrates, schematically, the steps of an enzymatic synthesis process involving the enzymatic synthesis apparatus of Figure 1.

The characteristics, variants and different embodiments of the invention can be associated with each other, in various combinations, as long as they are not incompatible or exclusive. in relation to each other. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described subsequently in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage and/or to differentiate the invention. compared to the prior art.

In the figures, elements common to several figures retain the same reference.

Figures i and 2 thus illustrate, schematically, an enzymatic synthesis apparatus comprising at least one inkjet printing device 1, such a printing device 1 being configured for the enzymatic synthesis of polynucleotides. These polynucleotides can be biomolecules such as DNA and/or RNA molecules, whether in the form of single strands or double strands.

The printing device i comprises a print head 2 equipped with nozzles 4, one of these nozzles 4 being particularly visible in Figure 2. The printing device 1 is configured so that ink 6 can circulate from from the ink cartridges to the nozzles 4. The ink 6 used in the printing device 1 contains enzymatic synthesis reagents which are necessary for an elongation reaction. These enzyme synthesis reagents may include a nucleoside triphosphate, the 3' end of which is protected, as well as an elongation enzyme. This elongation enzyme can for example be a polymerase: if the molecule to be synthesized is a DNA molecule, the polymerase will be a DNA polymerase, while if an RNA molecule is sought, the polymerase will be an RNA. polymerase. The nucleoside triphosphate contained in the enzymatic synthesis reagents is protected, that is to say it is associated with a protecting group of formula -R1NR2 ² where Ri is chosen from H, O, -COOH, CN, a group linear or branched alkyl of 1 to 6 carbon atoms, an aryl group, preferably chosen from H, O, a linear or branched alkyl group of 1 to 6 carbon atoms, and where R ₂ is chosen from H or an alkyl group linear or branched from 1 to 6 carbon atoms, so as to block its elongation. In a preferred embodiment, the protecting group is an aminoxyl. As mentioned previously, the ink 6 used in the printing device i can be stored in ink cartridges. Thus, the number of ink cartridges depends on the number of nucleoside triphosphates protected at their 3' end necessary for the elongation reaction and available in the printing device 1. These nucleoside triphosphates can be modified adenine, cytosine modified, modified guanine, modified thymine and/or modified uracil. Therefore, there may be, as illustrated in Figure 1, a first ink cartridge 8 for the ink 6 containing the modified adenine and the elongation enzyme, a second ink cartridge 10 for the ink 6 containing the modified cytosine and the elongation enzyme, a third ink cartridge 12 for the ink 6 containing the modified guanine and the elongation enzyme and a fourth ink cartridge 14 for the ink 6 containing modified thymine and/or modified uracil and elongation enzyme.

Without departing from the context of the invention, each ink within the ink cartridges may comprise, alone or in combination with other reagents, a viscosity modifier, a surfactant, a dye which may be useful for subsequent imaging, a humectant, a cosolvent, a cofactor or others.

The enzymatic synthesis reagents present in the ink 6 are intended to be deposited on a substrate plate 16. This substrate plate 16 can be glass, silica, silicon oxide, plastic, metal or similar surfaces, but also other surfaces such as for example biological tissues. It can be transparent, semi-transparent, opaque, colored or uncolored. It can also have a two-dimensional configuration, in particular with portions with hydrophobic or hydrophilic properties, or in three dimensions, with wells delimiting the reaction sites within them. Such a substrate plate 16 is here placed on a support platform 18, which will be described subsequently and which in particular allows the movement of the substrate plate 16 between various stations or operating stations of the enzymatic synthesis apparatus, or even within the same operating station. It is thus understood that the substrate plate 16 is mobile within the enzymatic synthesis apparatus. Such mobility can for example be implemented by computer control, in particular via software installed on a computer. This substrate plate 16 is more particularly arranged on a reception zone 20 of the support platform 18. This reception zone 20 is carried by a partition of the support platform 18 which is opposite the print head 2. The receiving zone 20 is configured to receive the substrate plate 16 and hold it in position, for example during movements of the support platform 18 within the enzymatic synthesis apparatus.

The substrate plate 16 includes several reaction sites. Each reaction site is distinct from other reaction sites and they do not overlap; in other words, the reaction sites are not contiguous. Each reaction site contains at least one initiator whose 3' end is free, also called initiator fragment. This initiator fragment is a short nucleotide fragment whose elongation results in a polynucleotide, which can be a DNA polynucleotide if the initiator fragment is a DNA fragment or even an RNA polynucleotide if the initiator fragment is a DNA fragment. 'RNA. The reaction sites are for example arranged in rows, these rows extending perpendicular to a longitudinal direction L corresponding to a main direction of extension of the substrate plate 16. The rows are arranged successively on the substrate plate 16 according to this longitudinal direction L.

The enzymatic synthesis apparatus and its printing device 1 are implemented as part of a method for the enzymatic synthesis of such polynucleotides. This method of enzymatic synthesis involves various steps, with the completion of these steps forming a cycle. At the end of a cycle, at least some of the initiator fragments will have been elongated by one nucleotide each. The repetition of several cycles leads to the synthesis of polynucleotides, and the appropriate selection of the type of ink, that is to say the type of nucleoside triphosphates projected at a given time on a given reaction site, at each cycle allows to obtain polynucleotides of a predetermined sequence.

As mentioned previously, the support platform 18 is mobile. It can thus be moved, within the enzymatic synthesis apparatus, to a printing station comprising the printing device 1 and within which of the ink 6 can be deposited on the substrate plate 16. For this purpose, the receiving zone 20 carrying the substrate plate 16 is positioned under the print head 2 of the printing station and more precisely under the projection nozzles 4 of this print head 2. When the reception zone 20 is facing the print head 2, the support platform 18 is in a first position which is illustrated in Figure 2.

Once the substrate plate 16 carried by the support platform 18 is adequately positioned under the print head 2, i.e. in its first position, ink 6 is ejected by the nozzles 4, as shown in Figure 2. These nozzles 4 thus deliver drops of ink to the reaction sites of the substrate plate 16, which allows the deposition of enzymatic synthesis reagents in these reaction sites. Such deposition can be facilitated by the movement of the print head relative to the substrate plate 16, so that the nozzles 4 of this print head can be positioned successively opposite each row of reaction sites. More particularly, it is the substrate plate 16 and the support platform 18 which are moved relative to the print head but certain printing modes can provide that the substrate plate and the print head are all two able to move to optimize this deposit operation.

The role of the elongation enzyme contained in ink 6 is to extend the initiator fragments present in the reaction sites, using nucleoside triphosphates modified so that their 3' ends are protected and which are also contained in ink 6. More precisely, the elongation enzyme adds a single modified nucleotide to a free 3' end of a terminating nucleotide of a given initiator fragment, which generates an elongated initiator fragment. Due to the modified nature of the nucleotides which are blocked at their 3' end, for example with an aminoxyl protecting group, in a given drop of ink, once a first nucleotide modified in this way is grafted to the fragment initiator, no other nucleotide can be grafted since the free end of the strand thus formed is protected. In other words, for a given drop of ink, only one of the nucleotides present in the drop is capable of being linked to the free terminating nucleotide of the initiator fragment. This protection ensures that Nucleotides are added to the initiator fragment one by one for each cycle, thus avoiding errors in the polynucleotide sequence.

The elongation reaction can occur during an incubation step, which corresponds to a duration necessary for this elongation. During this incubation step, a cover 22 is according to the invention placed on top of the substrate plate 16 to facilitate elongation. Such a cover 22 and its deposit on the support platform 20 will be described in more detail below. In particular, the benefit of this cover will be described in preventing the evaporation of the ink drops projected onto the substrate plate, in heating the drops during the incubation step and/or the imaging step, in make it possible to carry out deprotection, washing and drying functions in small volumes in particular by forming an appropriate fluid circulation conduit, and/or to allow in this context imaging in an appropriate imaging station.

The enzymatic synthesis method subsequently comprises a deprotection step, during which the elongated fragments protected at their 3' ends are deprotected to form elongated fragments having a free 3' end. The deprotection step is therefore a removal of the protective groups from the elongated fragments, so that the elongated fragments can be elongated again in a subsequent cycle. The deprotection step is carried out by a deprotection solution which contains specific reagents such as reducing agents or even enzymatic cleavage enzymes. The substrate plate 16 carried by the support platform 18 can for example be immersed in a bath of this deprotection solution for the implementation of this deprotection step. The deprotection step can be followed by a cleaning step within a cleaning station of the enzymatic apparatus, during which the substrate plate 16 is immersed in a bath of washing or rinsing solution. In each of these stages, the support platform can be lowered gently to the surface of a liquid, with the substrate plate devoid of a cover to facilitate immersion of the reaction sites.

Alternatively, the cover can be left in position on the support platform and configured to form a circulation conduit of fluid between the substrate plate and itself, the deprotection solution then being pushed through this circulation conduit. In this context, it is advantageous for the height of the fluid circulation conduit to be limited to a few millimeters, or to a few tens of millimeters at most, to limit the quantity of liquid used for the deprotection operation.

These two scenarios also apply to the use of a cleaning operation of the substrate plate, the deprotection solution then being replaced by a cleaning liquid.

The enzymatic synthesis apparatus may, as part of the operating stations mentioned above, include an imaging station. Such an imaging station, which allows verification of the progress of the enzymatic synthesis, comprises a microscope incorporating a digital camera 24 which is implemented in the context of detecting the presence and/or positioning of the drops of ink on the substrate plate 16. The camera 24 thus generates images of the substrate plate 16. Such images are then processed by software integrated into the printing device 1, this software being capable of analyzing information such as the presence, absence, size, shape or even content of the ink drops deposited on the substrate plate 16, for example to ensure that the ink drops do not overlap or have not overwhelmed the reaction sites. In other embodiments not illustrated here, the imaging station can be equipped with two cameras offset from each other relative to the substrate plate 16, to produce stereoscopic images.

The cover 22, which is intended to cover the substrate plate 16, will now be described in more detail in relation to Figures 3 to 8.

In each of the embodiments which will be described, the cover 22 is configured to be deposited on the support platform 18 covering the substrate plate 16, at least for the duration of the incubation of the enzymatic synthesis, and removed from this according to a mechanism which will be described later. According to the embodiments, and in particular the possibility of carrying out an imaging operation through a transparent wall of the cover, or even the possibility of letting a deprotection or deprotection fluid pass through. cleaning through a circulation conduit formed between the cover and the support platform, the cover can be left in position on the support platform for a longer or shorter time, between two inkjet printing operations during which the cover must be removed and return to its original position, away from the support plate.

The cover 22 has a substantially parallelepiped shape. It is composed of longitudinal 26 and lateral 28 walls joined to each other to form the periphery of the cover. The cover 22 further comprises an upper wall 30 and a lower wall 32, which are opposed to each other and joined by the longitudinal walls 26 and lateral walls 28.

The upper 30, lower 32, longitudinal 26 and lateral 28 walls define a volume of the cover 22. Within this volume, the cover 22 has a cavity 34 configured to accommodate the substrate plate 16 and dimensioned for this purpose when the cover is reported against the support platform. Such a cavity 34 is particularly visible in Figures 4 to 7. The cavity 34 corresponds to a recess within the volume of the cover 22 made from the lower wall 32. The dimensions of the cavity 34 are adapted to the dimensions of the substrate plate, in particular so that all of the reaction sites are covered by the cover without the cover crushing one of the reaction sites. Preferably, in order to facilitate the fixing of the cover and subsequently the unhooking of this cover without moving the contents within the reaction sites, the dimensions of the cavity are adapted so that the entire substrate plate is housed inside the cavity and that the lower wall 32 of the cover is in contact with the support platform and not with the edges of the substrate plate.

As mentioned previously, the cover 22 makes it possible to facilitate the elongation of the initiator fragment and/or of the polynucleotide being elongated, during the incubation step. It is in fact necessary, for this elongation to take place under optimal conditions, to ensure that the drops of ink which have been deposited on the substrate plate 16 do not dry and to avoid their evaporation during the processing. incubation period necessary for this elongation. THE cover 22 is for this purpose equipped with a means of humidifying the substrate plate 16.

Different means can also be integrated into the cover, such as for example, without this list being exhaustive, at least one among means for heating the substrate plate, means for heating transparent walls which can equip the cover to avoid condensation on these transparent walls, or means forming passages for a liquid or air within the cover, additionally or alternatively to the presence of the circulation conduit previously mentioned and formed between the cover and the platform support.

The humidification means comprises a reservoir 35 provided in the cover 22. The reservoir 35 is configured to receive a fluid allowing the humidification of the substrate plate, which is for example a saturated saline solution. The fluid intended to be loaded into the tank can be preheated, or heated during the process.

The reservoir 35 thus constitutes a storage space for the fluid allowing humidification. The reservoir 35 can for this purpose be a cartridge of the saturated saline solution or even a compartment capable of receiving this solution via a syringe. Such a saturated saline solution may for example comprise ammonium nitrate, ammonium sulfate, magnesium chloride, magnesium nitrate, lithium chloride, potassium sulfate, potassium chloride, acetate potassium hydroxide, sodium chloride, sodium nitrite, sodium dichromate, or a mixture of two or more of these elements. A choice among these solutions can be made depending on the desired humidity level.

According to the invention, the humidification means, here the reservoir 35, is able to cooperate with the cavity 34. The saturated saline solution can thus load with humidity, from the reservoir 35, the air present or brought to penetrate into the cavity 34 of the cover 22.

In a first embodiment, illustrated in Figures 3 and 4, the reservoir 35 is arranged within the volume of the cover 22 and it extends close to the upper wall 30, at a distance from each of the longitudinal 26 and lateral walls 28. The reservoir 35 may consist of a clearance of material formed within the cover 22 from the upper wall, to receive a cartridge of humidification product, or else consist in a closed cavity within the cover, intended to directly receive humidification product. The reservoir 35 is moreover substantially parallel to planes in which this cavity 34 and the substrate plate 16 mainly extend, so that the reservoir 35, the cavity 34 and the substrate plate 16 when it is received in the cavity are superimposed in this order from the upper wall to the lower wall of the cover. In this first embodiment, the positioning of the reservoir, covering the substrate plate, can interfere with the imaging necessary after incubation to ensure that the reaction sites are filled as desired, and it It may be preferable to remove the cover to perform these imaging operations. However, the tank can be equipped with transparent windows, with one which forms part of the upper wall of the cover and the other which is placed between the tank and the cavity, imaging can be carried out through the transparent windows and the fluid present in the reservoir as long as the fluid, which is for example the saline solution, does not present swirls or bubbles on the surface.

In a second embodiment, illustrated in Figures 5 and 6, the reservoir 35 is again arranged within the volume of the cover 22, but this time around the cavity. The reservoir 35 forming the humidification means is a chamber delimited laterally by a low wall 37 helping to delimit both the cavity 34 and the chamber 35. A fluid capable of generating humidity is placed at the bottom of the chamber 35 and the humidity can pass into the cavity 34 via a passage 370 made between the chamber and the cavity opposite the bottom wall of the chamber. More particularly, the low wall 37 extends partially over the height of the chamber to form the passage between the chamber and the cavity. In this way, the wall 37 is configured so that the humidity can pass from the chamber to the cavity while maintaining the fluid within the chamber, at a distance from the substrate plate housed in the cavity. The longitudinal walls 26 and side walls 28 have a recess 27 to form a receiving surface for a transparent window 39, visible in Figure 6 and forming part of the upper wall 30.

In this second embodiment, the positioning of the reservoir, on the periphery of the cavity, does not interfere with the imaging which is carried out through the transparent window, and it is possible to leave the cover in place.

Furthermore, Figure 6 makes visible a possible characteristic of the invention according to which the cover, here in the chamber 35, can be equipped with heating means 41 making it possible here to maintain the fluid in a state generating humidity. These heating means can be active means, controllable remotely for example, or else passive means such as Kapton sheets for example.

In each of these two embodiments, the reservoir 35 can be filled with a fluid intended to remain within the reservoir during all of the cycles of enzymatic synthesis, that is to say during several successive incubation periods. For example. Alternatively, the fluid can be emptied and the tank refilled at each cycle.

In a third embodiment shown in Figure 7, the cover comprises a fluid inlet 36 as well as a fluid outlet 38. More precisely, the fluid inlet 36 and the fluid outlet 38 are channels each provided in one of the walls of the cover, here the longitudinal walls. The fluid inlet 36 and the fluid outlet 38 open more specifically into the cavity 34, so that they communicate fluidly with this cavity 34. The fluid inlet 36 and the fluid outlet 38 can be arranged facing each other. 'one from the other on opposite walls of the cover 22, without this however being limiting to the invention. The number of fluid inlets and fluid outlets provided in this second embodiment can be variable as long as there is at least one fluid inlet. The fluid inlet 36 thus makes it possible to convey fluid within the cover 22 and the possible fluid outlet 38 makes it possible to evacuate it if necessary.

In this third embodiment, the fluid circulating from the fluid inlet 36 to the fluid outlet 38 may be a wet fluid, for example a mixture of dry gas and water, the passage of which aims to ensure the humidification of the substrate plate 16 when the cover 22 covers it. In this context, the fluid inlet and the fluid outlet form a humidification means, which ensures the humidification of the substrate plate 16 when the cover 22 covers it. Such a humid fluid can be generated by a device such as a central humidifier, a turbine humidifier, an ultrasonic humidifier, an evaporator or even a steam vaporizer. This apparatus can be arranged within the enzymatic synthesis apparatus and connected to the fluid inlet 36 and to the fluid outlet 38 by conduits. The device can also have a function of purifying the fluid, in particular by removing allergens and pollutants. The circulation of the fluid from the fluid inlet 36 to the fluid outlet 38 can be part of a circulation loop or, to avoid contamination between two enzymatic synthesis cycles, be one-way. Such circulation of the fluid can also be implemented via a pump, for example a pump fluidly connected to the cleaning station mentioned above.

Furthermore, the fluid inlet 36 and the fluid outlet 38 can be crossed by other types of fluid, and for example a washing fluid or a deprotection fluid as they may have been mentioned previously.

Although not shown in the figures, one could without departing from the scope of the invention consider an alternative embodiment which would associate a reservoir 35 of saturated saline solution such as that of the first or second embodiment with a fluid inlet 36 and a fluid outlet 38 such as those of the third embodiment. In such an alternative embodiment, the reservoir 35 could for example be provided within the support platform 18 or arranged within the enzymatic synthesis apparatus and it would be fluidly connected to the fluid inlet 36 and to the fluid outlet 38 of the cover 22. It is understood here that the fluid circulating from this fluid inlet 36 to this fluid outlet 38 would be the saturated saline solution, the fluid inlet and outlet 36, 38 of the cover 22 then constituting means of communicating the reservoir 35 to the substrate plate 16. According to yet another alternative embodiment, the reservoir 35 of saturated saline solution could be provided in the support platform 18 and include other means of communication with the substrate plate 16, which would then no longer be carried by the lid. Such means of communication could for example take the form of pins which would be lowered when the cover 22 is placed on the support platform 18, these pins otherwise constituting a barrier between the reservoir 35 provided in this support platform 18 and the substrate plate 16 which it carries in its reception zone 20.

Whatever the embodiment, the cover 22 can be equipped with a humidity sensor and/or a temperature sensor in order to control the operation of the humidification means.

The cover 22 may also include a heating element, not shown here, which helps to prevent the formation of condensation within the cover 22, which could hinder imaging operations.

According to the invention and as illustrated in Figures 3 to 8, the cover 22 is equipped with reversible attachment means 40 to a frame 42 of a covering station of the enzymatic synthesis apparatus, this frame 42 being visible in Figure 8. These reversible attachment means 40 allow the cover 22 to be alternately placed on the support platform 18 from the frame 42 and lifted from this support platform 18 to attach to the frame 42. The cover 22 is more particularly intended to cover the substrate plate 16; we understand that it will rest for this purpose on the reception zone 20. These reversible attachment means 40 are configured to cooperate with reversible attachment members which are carried by the frame and which will be detailed later in the description .

According to one embodiment of the invention, the reversible attachment means 40 comprise magnets including at least one electromagnet. The activation and deactivation of the reversible attachment means are then done respectively by the electrical supply of the electromagnet and the power cut-off at the appropriate time. As an example of an operating mode of the invention, the at least one electromagnet is powered continuously so that the cover is retained on the frame 42 and the power supply is interrupted when the cover must be released to cover the substrate plate.

The reversible attachment means 40 may also comprise at least one permanent magnet, a combination of the presence of at least one electromagnet and at least one permanent magnet making it possible to ensure that the cover 22 is maintained in position on the frame. 42 even in the event of a cut in the electrical supply necessary for the operation of the electromagnet. Where applicable, if sufficient permanent magnets are provided, this may make it possible to avoid a continuous supply of electromagnet(s) to retain the cover to the frame and this may thus make it possible to limit electrical consumption.

As is particularly visible in Figures 3, 5 and 7, the reversible hooking means 40 are carried by the upper wall 30 of the cover 22. Thus, the reversible hooking means 40 are arranged on a wall opposite the wall to from which the cavity 34 extends, namely the lower wall 32. The upper wall 30 here comprises four electromagnets as reversible attachment means 40, these electromagnets each being arranged at a corner of the upper wall 30, c that is to say on either side of the cavity 34. Such an arrangement of the reversible attachment means 40 makes it possible to ensure that the substrate plate 16 is correctly covered by the cover 22, this substrate plate 16 being surrounded by the reversible attachment means 40.

Alternatively, and although not shown in the figures, the reversible attachment means 40 of the cover 22 to the frame 42 could take the form of at least one suction member, for example a suction cup.

As mentioned, the reversible hooking means 40 are configured to cooperate with reversible hooking members 44 of the frame 42 of the recovery station. These reversible attachment members 44 are in particular, if the reversible attachment means are electromagnets and/or permanent magnets, magnets or metal inserts.

The reversible attachment means 40 can be activated or deactivated, their deactivation leading to the detachment of the cover 22 from the frame 42 of the covering station, that is to say the separation of these two elements, as well as the deposit of the cover 22 on the reception zone 20 of the support platform 18 carrying the substrate plate 16, while their activation causes a lifting of the cover 22 of the support platform 18 and its reversible attachment to the frame 42.

It is thus understood that the reversible hooking means 40 allow, when they are activated and deactivated, and the support platform 18 is facing the frame 42, respectively attraction and repulsion movements of the cover 22 relative to the frame 42. The attraction allows the cover 22 to be reversibly attached to this frame 42, while the repulsion allows its detachment and therefore its deposit on the reception zone 20 of the support platform 18. Such movements of attraction and repulsion are, due to the arrangement of the reversible attachment means 40, substantially perpendicular to a plane in which the support platform 18 mainly extends.

The reversible attachment means 40 are activated as a function of a position of the support platform 18 and of the substrate plate that it carries, and more precisely of the position of the substrate plate relative to the cover retained on the built.

The reversible attachment means 40 can be activated remotely, in particular by an appropriate computer program, as soon as the positioning of the support platform 18 in an appropriate position is detected within the printing device 1.

In order to ensure optimal positioning of the cover 22 relative to the substrate plate 16, the cover 22 and/or the support platform 18 may have keying means. These keying means are more precisely carried, for the cover 22, by the lower wall 32.

Furthermore, the cover 22 may comprise, as illustrated in Figure 4 or Figure 8 in particular, reversible fixing instruments 220, which are configured to cooperate with reversible fixing systems 180 arranged on the support platform 18 for facilitate the unhooking step during which the cover is placed on the support platform, by attracting the cover towards the support platform, or on the contrary to facilitate a step of returning to the original position, during which the lid is brought back against the cover station frame, pushing the cover away from the support platform.

An enzymatic synthesis process 46 involving the enzymatic synthesis apparatus as mentioned previously will now be described in relation to FIG. 8. The enzymatic synthesis process 46 according to the invention comprises several successive steps which form a cycle allowing the implementation of the synthesis method described previously.

The enzymatic synthesis process 46 begins with a first positioning step El, during which the support platform 18 is positioned within the printing station so that the reception zone 20 carrying the substrate plate 16 is in position. view of the print head 2, that is to say in its first position.

The substrate plate 16 is then positioned under the projection nozzles 4 carried by this print head. The enzymatic synthesis process 46 then continues with the printing step, mentioned previously in relation to the enzymatic synthesis method, which allows the deposition of ink 6 containing enzymatic synthesis reagents in the reaction wells of the plate substrate 16 provided for this purpose. Then comes a second positioning step E2, during which the support platform 18 is moved to a second position within the covering station so that the substrate plate is positioned under the cover 22 which is hooked to the frame 42 thanks to the reversible hooking means 40, which are for this purpose in a first state, for example activated, and to the reversible hooking members 44. The cover 22 can then be placed on the reception zone 20 of the platform support 18 overlapping the substrate plate 16, which constitutes a step E3. Such an unhooking step E3 notably involves the reversible hooking means 40 and the reversible hooking members 44, with at least the reversible hooking means which change state, and are here for example deactivated. At its end, the lower wall of the cover 22 is in contact with the reception zone 20 and the substrate plate 16 is housed in the cavity 34 of the cover 22. If necessary, the unhooking step also implements the systems reversible fixing 180 and/or the reversible fixing instruments 220, to attract the cover 22 towards the support platform 18. This has the advantage on the one hand of ensuring reliability of the positioning of the cover 22 on the support platform 18 and speed of the unhooking operation, by making the fixing systems and instruments cooperate, and on the other hand to freeze the position of the cover 22 once on the support platform.

Once the cover 22 is positioned to cover the substrate plate 16, the enzymatic synthesis process 46 continues with a humidification step E4 via the humidification means, which makes it possible to avoid drying out of the drops of ink containing the synthesis reagents which were deposited on the substrate plate 16 during the printing step. Thus, the elongation step mentioned previously in relation to the enzymatic synthesis method can take place under optimal conditions, the humidification step E4 being able to take place throughout the duration of the incubation step of this method. of synthesis.

The humidification step E4 involves the humidification means, that is to say according to the embodiments the reservoir 35 and/or the fluid inlet 36 and the fluid outlet 38. For the modes of embodiment involving the reservoir 35, humidification is ensured by diffusion of the saturated saline solution within the cavity 34, and therefore around the substrate plate 16. For the embodiments comprising the inlet and outlet of fluid 36, 38, the circulation of the wet fluid between this fluid inlet 36 and this fluid outlet 38 can be ensured by actuation of the pump connected to the cleaning station.

Following the humidification step E4, the support platform 20 can be moved to the imaging station comprising the camera 24 for an imaging step E5. Such an imaging step E5 is facilitated by the transparency of at least one wall of the cover 22. Operations to verify the elongation can then be carried out.

The support platform 18 can then return to the covering station and resume the second position previously mentioned, for an attachment step E6, during which the cover 22 is lifted from the reception zone 20 and attached to the frame 42 of the recovery station. A such hooking step E6 corresponds to a change of state of the reversible hooking means 40 and/or the reversible hooking members 44, and it may also include a change of state, namely an activation or deactivation , reversible fixation systems 180 and reversible fixation instruments 220.

Once the cover 22 is attached to the frame 42, the support platform 18 can be directed towards other operating stations of the enzymatic synthesis apparatus, for example the cleaning station for a rinsing step E7 of the plate. substrate 16. Another cycle of the enzymatic synthesis process 46 can then begin by reproducing the first positioning step El.

The present invention thus proposes a cover configured to cover a substrate on which drops of synthesis reagents have been deposited, thus making it possible to control a degree of humidity necessary for the progress of the synthesis, and means allowing simplified and rapid fixing of this cover.

The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

1. Enzymatic synthesis apparatus configured for the synthesis of biomolecules, comprising a print head (2) equipped with nozzles (4), a support platform (18) comprising a reception zone (20) configured to receive a plate of substrate (16), said substrate plate (16) being capable of receiving drops of ink (6) containing synthesis reagents, said drops of ink (6) being ejected by the nozzles (4), the apparatus enzymatic synthesis comprising a cover (22) intended to cover the substrate plate (16), the cover (22) being equipped with reversible attachment means (40) to a frame (42) of a covering station of the enzymatic synthesis apparatus. 2. Enzymatic synthesis apparatus according to the preceding claim, in which the cover (22) is configured to form with the support platform (18), when it is placed against this support platform, a cross fluid circulation conduit on which the substrate plate (16) is arranged. 3. Enzymatic synthesis apparatus according to one of the preceding claims, wherein the cover (22) is equipped with means for humidifying the substrate plate (16). 4. Enzymatic synthesis apparatus according to the preceding claim, wherein the humidification means comprises a fluid inlet (36) and a fluid outlet (38), said inlet (36) and said outlet (38) being provided in the cover (22). 5. Enzymatic synthesis apparatus according to claim 3, wherein the humidification means comprises a reservoir (35) configured to allow passage of humidity from the reservoir to the substrate plate. 6. Enzymatic synthesis apparatus according to the preceding claim, in which the reservoir (35) is provided in the cover (22). 7. Enzymatic synthesis apparatus according to any one of the preceding claims, wherein the cover (22) is equipped with a humidity sensor and/or a temperature sensor. 8. Enzymatic synthesis apparatus according to any one of the preceding claims, in which the reversible attachment means (40) are configured to cooperate with reversible attachment members (44) of the frame (42) of the recovery station . 9. Enzymatic synthesis apparatus according to any one of the preceding claims, in which the reversible attachment means (40) and/or the reversible attachment members (44) comprise at least one electromagnet. 10. Enzymatic synthesis apparatus according to the preceding claim, in which the reversible attachment means (40) and/or the reversible attachment members (44) comprise at least one permanent magnet. 11. Enzymatic synthesis apparatus according to any one of claims 1 to 8, in which the reversible attachment means (40) and/or the reversible attachment members (44) comprise at least one suction member. 12. Enzymatic synthesis apparatus according to any one of the preceding claims, wherein the support platform (18) comprises reversible fixing systems (180), the reversible fixing systems cooperating with reversible fixing instruments (220) arranged on a lower wall of the cover (22) facing the support platform (18). 13. Enzymatic synthesis apparatus according to any one of the preceding claims, in which the cover (22) is made at least partly of a transparent material. 14. Enzymatic synthesis apparatus according to any one of the preceding claims, wherein the cover (22) comprises a heating element. 15. Enzymatic synthesis method (46) by an enzymatic synthesis apparatus according to any one of the preceding claims, comprising a first positioning step (El) during which the support platform (18) carrying the substrate plate (16) is positioned, within a printing station, under a print head (2) of the enzymatic synthesis device so that the reception zone (20) of the substrate plate (16) is positioned opposite said print head (2), a printing step during which drops of ink (6) containing synthesis reagents are deposited on the substrate plate (16), a second positioning step (E2) during which the support platform (18) is positioned in the covering station facing the cover (22) so that the substrate plate (16) ) is positioned under the cover (22), and an unhooking step (E3) during which the cover (22) is deposited on the support platform (18) covering the substrate plate (16) by a change status of at least the reversible attachment means (40).