WO2018015543A1 - Pipette tip for an automated pipetting device - Google Patents

Abstract

The invention relates to pipette tips (1) for connecting to a pipette tube (2) of a pipetting device, which are used for taking up and discharging fluids. The pipette tip (1) according to the invention is in the shape of an elongated tube forming a pipette body (4), which has an opening (5) at one end and is designed for connecting to the pipette tube (2) at the other end, wherein the pipette tip (1) has a first electrode (7) as a volume measuring electrode of a measuring capacitor and a second electrode (10) as an immersion detector electrode, wherein the first electrode (7) is located on an outer surface of the pipette body (4) or is embedded in the pipette body (4), and the second electrode (10) is located at least partially on an inner surface of the pipette body (4). The invention also relates to pipetting devices having a pipette tip (1) of this type, a method for determining the volume of a sample fluid in a pipette tip (1) of this type, a method for detecting a pipette tip (1) of this type on a pipetting device, a method for producing a pipette tip (1) of this type, uses of a pipette tip (1) of this type, and a set of pipette tips (1) of this type.

Description

 PIPETTLE TIP FOR AN AUTOMATED PIPETTING DEVICE

RELATED APPLICATIONS

The present application claims the priority of Swiss patent application CH 00950/16 with filing date July 22, 2016, the content of which is hereby incorporated into the present application

Patent application is included, the priority of

Swiss patent application CH 00159/17 with filing date 10 February 2017, the content of which is hereby incorporated by reference

The priority of Swiss patent application CH 00523/17 with filing date April 19, 2017, the content of which is hereby incorporated into the

this patent application is incorporated.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the technical field of automated fluid processing systems, and more particularly relates to pipette tips, especially disposable tips (namely, disposable tips, abbreviated "DiTis") for pipetting, ie, aspirating and / or dispensing, of liquids. Furthermore, the present invention relates to pipetting devices with such Pipette tips, method for determining the volume of a sample liquid in such pipette tips, method for detecting such pipette tips on a

Pipetting device, method for producing such pipette tips, uses of such pipette tips and a set of such pipette tips.

BACKGROUND OF THE INVENTION

When in medical, chemical, analytical or pharmaceutical laboratories large quantities of samples too

Today, mostly automated laboratory systems or systems are used, which ensure rapid and reliable processing of each individual sample

enable. Such laboratory systems are often called

 Fluid handling systems designed to handle fluid volumes. Such

Liquid processing systems include in particular

Pipettor both for sucking and dispensing

Liquids or dispensers exclusively for dispensing liquids. Most laboratory applications require very precise pipetting operations around one

to obtain satisfactory analytical accuracy. Consequently, an accurate knowledge of the processed

Sample volumes or liquid volumes of crucial importance. In the Swiss patent application CH 00950/16 with filing date July 22, 2016, a method which provides an accurate determination of a processed (ie aspirated or

dispensed) liquid volume during pipetting, as well as a pipetting device, which uses this method for a precise determination of the processed sample quantities or liquid volumes,

proposed.

Many applications use a fresh pipette tip to handle each new sample. Such

Therefore, pipette tips are designed for single use and are commonly referred to as "disposable pipette tips" or English as "disposable tips" (abbreviated to "DiTis"). Depending on the application will be

 Pipetting different pipette tips used. It is therefore important that in an automated

Pipetting device, this is able to detect, if any, a pipette tip on the pipette tube

connected, and in particular whether the correct

Pipette tip is connected.

In the Swiss patent application CH 00159/17 with filing date February 10, 2017, a method which the

Detection of a pipette tip on one

Pipetting device allowed, as well as a

Pipetting device, which can automatically detect different pipette tips by this method, proposed. In the Swiss patent application CH 00523/17 with filing date April 19, 2017, a method is provided which allows a determination of the volume of a sample liquid in a proposed pipette tip.

There is a problem in the art that the

Determining a volume of a sample liquid with low electrical conductivity can be inaccurate.

There is thus a need to provide suitable pipette tips which can be used to determine the volume of a sample liquid of low electrical conductivity in such a pipette tip and to detect such pipette tips on a pipetting device.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a pipette tip for connection to a pipette tube of a pipetting device, with the aid of a precise determination of the volume of a

Sample liquid in the pipette tip even then

is enabled when the sample liquid has a low electrical conductivity. This task will according to the invention by the specified in claim 1

Pipette tip met.

It is another object of the present invention to provide a pipetting apparatus with a pipette tube for

fluid-tight connection of a proposed

To provide pipette tip at one end, wherein at the pipetting a respective connected pipette tip is precisely detected. This object is achieved according to the invention by the set in claim 13 pipetting device.

It is a further object of the present invention to provide a method which can accurately determine the volume of a sample liquid in one

proposed pipette tip even if the sample liquid has a low electrical

Has conductivity. This object is achieved by the proposed in claim 19

Determination procedure solved.

It is a further object of the present invention to provide a method that allows the proposed pipette tip to be detected on a pipetting device. This object is achieved according to the invention by the recognition method proposed in claim 21. It is another object of the present invention to provide a method for producing a proposed

To provide pipette tip. This task will

solved according to the invention by the production method proposed in claim 22.

It is another object of the present invention to provide a use of a proposed pipette tip, wherein use of the volume of a sample liquid in the pipette tip is reliably determined even if the sample liquid has a low electrical

Has conductivity. Such an inventive use is specified in claim 24.

Further, it is an object of the present invention to provide a set of pipette tips suitable for use with the proposed detection method

are suitable. Such an inventive set of pipette tips is recited in claim 26.

Specific inventive embodiments are given in the dependent claims.

A pipette tip according to the invention is provided for connection to a pipette tube by a pipetting device and shaped as an elongate tube which forms a pipette body having at its one, first end an opening for aspirating and / or dispensing Liquids, and at its other end for (fluid-tight) connection to the pipette tube

is formed, wherein the pipette tip a first

Having an electrode as a volume measuring electrode of a measuring capacitor and a second electrode as immersion detection electrode, wherein the first electrode is located on an outer surface of the pipette body or in

Pipette body is embedded and the second

Electrode is at least partially located on an inner surface of the pipette body. By the wording "with the second electrode at least partially on an inner surface of the pipette body" it is meant that the second electrode is at least partially exposed to the interior of the pipette body. In this case, the second electrode may be partially embedded in the material of the pipette body in such a way that it is still partly or partially exposed to the interior of the pipette body. It does not matter whether the second electrode is embedded in the pipette body or even at least partially along the outer surface of the

 Pipette body runs as long as one or more sections or contact points of the second electrode are still exposed to the interior of the pipette body and thus at least partially contact the liquid in the interior of the pipette body.

In one embodiment variant of the pipette tip, the first electrode and second electrode are electrically conductive and at least partially contact the second electrode the liquid on the inner surface of the

Pipette body galvanic.

In a further embodiment variant of the

Pipette body made of an electrically non-conductive

 Material, in particular a non-conductive plastic, such as non-conductive polypropylene, which

in particular acts at least as part of a dielectric of the measuring capacitor.

In a further embodiment variant of the pipette tip, the second electrode is arranged substantially outside the relevant measuring capacitor. Advantageously, the second electrode is outside the measuring capacitor. As a result, the parasitic capacitance through the second electrode can be negligible in comparison to FIG

Volume capacity. In one example, the first

Electrode and second electrode may be arranged substantially opposite to each other.

In a further embodiment variant of the pipette tip, the first electrode contains at least two first

Partial electrodes and the second electrode includes at least two second partial electrodes, wherein the first partial electrodes are arranged opposite to each other and the second partial electrodes are arranged opposite to each other. In a further embodiment of the pipette tip, the first electrode is elongated, in particular

formed in a strip shape, extends axially along the pipette tip, and rotates in particular in one

Angular range between 20 ° and 270 °, preferably in an angular range of 40 °.

In a further embodiment of the pipette tip, the first electrode is elongated, in particular

formed strip-shaped, extends axially along the pipette tip and is partially different widths, the first electrode in particular a

staircase-shaped width profile in the axial direction, and the width of the first electrode, e.g. at the first end is the lowest, and the width in the axial direction is gradually increased.

In a further embodiment variant of the pipette tip, the first electrode does not extend to the opening at the first end and is in particular spaced from this opening in a range of 3 mm to 6 mm, preferably in a range of 4 mm to 6 mm, particularly preferably 5 mm.

In a further embodiment of the pipette tip, the second electrode is strip-shaped and extends axially along the tube, and wherein they

in particular up to three quarters of the inner circumference of Circulates pipette tip, further in particular half of the inner circumference of the pipette tip rotates.

In a further embodiment of the pipette tip, the second electrode contacts the liquid in the

Pipette body at substantially predetermined

Contact points along the axial direction of the

Pipette body, wherein the contacting points in an angular range to each other between 90 ° and 270 °, preferably 180 °, are arranged. In the case of the aforementioned

 Execution of the pipette tip, in which the second electrode via contacting points with the liquid in the interior of the pipette body comes into contact, these contacting points, starting from the first electrode, be arranged alternately from both sides. In a

Embodiment, the contacting points are arranged in particular at 90 ° and 270 ° when the first electrode is at 0 °.

In a further embodiment of the pipette tip, the second electrode extends to the opening at the first end or the opening at the first end is at least partially formed by the second electrode.

In a further embodiment, the

Pipette tip a disposable pipette tip, which

is intended especially for single use. According to another aspect of the present invention, a pipetting device comprises at least one

Pipette tube, a pressure generating means and a

 (Capacitance) measuring unit, wherein the pipette tube is formed at its one, first end for fluid-tight connection of a proposed pipette tip, and is connected at its other end to the pressure generating means. In addition to the capacity (imaginary part of the complex

Impedance) can also change the resistive component (real part of the complex impedance). Thus, the skilled person understands that in addition to the capacity and the resistive portion is meant.

In one embodiment of the pipetting device, in a region for connecting the pipette tip, a first electrical contact for producing a

electrical connection, in particular a galvanic connection, with a first electrode as

Volume measuring electrode present, which is located on an outer surface of the pipette body or embedded in the pipette body. In one example, additionally or alternatively, a second electrical contact may be provided for establishing an electrical connection to a second electrode as a dip detection electrode located at least partially on an inner surface of the pipette body.

In a further embodiment of the

Pipetting device is the liquid in one Sample container, which is electrically conductively or capacitively coupled to a conductive work table surface which is connected to ground.

In a further embodiment of the

 Pipetting device is the first electrical contact via an electrical conductor connected to the measuring unit and is the second electrical contact via the liquid and a capacitive coupling of the liquid over the

Worktable surface connected to the measuring unit.

In a further embodiment of the

 Pipetting device, the measuring unit is designed to function as a function of a measured capacity of a

Measuring capacitor, which through the first electrode and at least part of one in the pipette tip

absorbable sample liquid is formed as a counter electrode, a volume in the pipette tip

determine and further configured to use the second electrode

 Immerse immersion of the pipette tip in the sample liquid.

In a further embodiment, the

Pipetting device further comprises a detection unit for detecting whether the pipette tip at the first end of

Pipette tube is connected, and / or for detecting a characteristic feature of the pipette tip based on a measurement of a further capacity, wherein the further capacity is dependent on one or more of the following properties:

- a material from which the pipette tip is made; - A geometry of the pipette tip, in particular a shape of the pipette tip, further in particular one

 Diameter and / or a length of the pipette tip;

- A coating of the pipette tip, in particular

 a material from the the coating of

 Pipette tip exists, more particularly one

 Extent or thickness of the coating of the

 Pipette tip;

- A material from the first and / or second

 Electrode consists; a geometry (such as a length, width, thickness

 or area) of the first and / or second electrode.

According to a further aspect of the present invention, a method for determining a volume of a sample liquid in a proposed pipette tip comprises the following steps (= determination method):

Measuring a capacitance of a measuring capacitor comprising a first electrode, which is located on an outer surface of the pipette body or in

Embedded in the pipette body, and a counterelectrode passing through at least part of a sample liquid, which is located in the pipette tip is formed;

Determining the volume of the sample liquid in the

 Pipette tip depending on the measured capacitance.

In one embodiment, this includes

Determination process continues the step:

- Detecting a dipping the pipette tip in the sample liquid by means of a second electrode as immersion detection electrode (or as immersion contact), wherein the second electrode is at least partially on an inner surface of the pipette body.

Another aspect of the present invention relates to a method for detecting (= recognition method) a proposed pipette tip on a

 Pipetting device with a pipette tube, which at its one, first end for releasably receiving a

Is formed pipette tip for aspirating or dispensing a liquid, and which is operatively connected at its other end to a pressure generating means, the method comprising measuring a capacity which is dependent on one or more of the following

Properties: - a material consisting of the pipette tip; - A geometry of the pipette tip, in particular a shape of the pipette tip, further in particular one

 Diameter and / or a length of the pipette tip;

- A coating of the pipette tip, in particular

 a material from the the coating of

 Pipette tip exists, more particularly one

 Extent or thickness of the coating of the

 Pipette tip;

- A material from the first and / or second

 Electrode consists;

a geometry (such as a length, width, thickness

 or area) of the first and / or second electrode.

According to another aspect of the present invention, a method of manufacturing (= manufacturing method) a proposed pipette tip comprises forming the pipette tip as an elongate tube constituting a pipette body from a first material, forming a first electrode from a second material at the pipette tip an outer surface of the

 Pipette body or embedded in the pipette body, and forming a second electrode of a third material on the pipette tip at least partially on an inner surface of the pipette body. In one example, the second material and the third material may be the same.

In a further embodiment, the steps of molding by means of a Mehrkomponentensprit zgussverfahrens, in particular the same Mehrkomponentensprit zgussverfahrens, sequentially or simultaneously with the molding of the pipette tip and the first and / or second electrode. In the case of production by sequential steps, in a first step, the non-conductive first material for molding the

Pipette tip to be injected. After this is solidified (e.g., about 6 seconds), the conductive second and third materials can be injected. Of course, further manufacturing processes can be realized.

A further aspect of the present invention relates to a use of the proposed pipette tip for determining a volume of a sample liquid, which is located in the pipette tip, with the aid of the first electrode as Volumenmesselektrode at the pipette tip, wherein the first electrode on an outer

Surface of the pipette body is located or im

Pipette body is embedded.

Another aspect of the present invention relates to a use of the proposed pipette tip for detecting immersion of the pipette tip into the sample liquid by means of the second electrode

Immersion detection electrode at the pipette tip, the second electrode at least partially the inner

Touched surface of the pipette body. According to another aspect of the present invention, a set of proposed pipette tips comprises at least two types of pipette tips, wherein the at least two types differ in that

Applying the proposed method of detecting a pipette tip, a capacity of a first type of

Pipette tips in a first region and the capacity of a second type of pipette tips is in a second region, wherein the first and second regions are non-overlapping, and wherein the at least two types in particular by one of the following features:

- volume of volume;

- Spit zenöffnungsgrösse / diameter for aspirating and dispensing a liquid;

- with or without filter to prevent

 Contaminations of the pipette tube during aspiration of a sample, and in particular a type of filter;

- purity category; - Usage;

- Volume measurement function;

- Sealing ability of a connection of the pipette tips to the pipette tube, and wherein in particular the outer geometry of the at least two types can be identical. It is expressly stated that the

above variants are arbitrarily combinable. Only those combinations of

Variants are excluded, which would lead to contradictions through the combination.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting embodiments of the present invention will be explained below with reference to figures. Show it:

Fig. La) is a schematic representation of a first

 Embodiment of an inventive pipette tip in a sectional view with each strip-shaped volume measuring electrode and

 Immersion detection electrode in a side view; b) schematic representation of the first

 Embodiment of an inventive pipette tip in a view from the front (on the volume measuring electrode); c) schematic representation of a second

 Embodiment of an inventive

Pipette tip with a staircase-shaped

Volume measuring electrode in a front view; Fig. 2a) is a schematic representation of the first

 Embodiment of an inventive pipette tip with strip-shaped

 Immersion detection electrode in one

 Cross-sectional view from above; b) a schematic representation of the second

 Embodiment of a pipette tip according to the invention with an immersion detection electrode as shown schematically curved in a cross-sectional view from above; c) a schematic representation of a third

 Embodiment of an inventive pipette tip with two first part electrodes and two second part electrodes in one

 Cross-sectional view from above; d) a schematic representation of a fourth

 Embodiment of a pipette tip according to the invention with a coating over the volume measuring electrode in a cross-sectional view from above;

Fig. 3a) is a schematic representation of a fifth

 Embodiment of a pipette tip according to the invention with a volume measuring electrode embedded in the pipette body and an immersion detection electrode on the inside

Surface of the pipette body in a view from the side; b) a schematic representation of the fifth

Embodiment of an inventive Pipette tip in a cross-sectional view from above;

Fig. 4a) is a schematic representation of a dip and

 Replacement process of a pipette tip in a container with a sample liquid; b) an illustrative time course of

 Capacitance of a measuring capacitor with

 Signal jumps when immersing and dipping the pipette tip into or out of the sample liquid; Fig. 5a) is a schematic representation of an aspiration and dispensing process a

 inventive pipette tip in the container with the sample liquid; b) an illustrative time course of

 Capacitance of a measuring capacitor with a linear signal rise and fall during aspiration and dispensing of the

 Sample liquid with the pipette tip;

Fig. 6a) is a schematic representation of a

 Aspiration process with a with

 Sample liquid of e.g. low

 Conductivity-filled pipette tip according to the prior art; b) a schematic representation of a

 Aspiration process with a with

 Sample liquid of e.g. low

Conductivity filled pipette tip in an embodiment of the invention; Fig. 7 is a schematic representation of a

 Embodiment of a pipetting device according to the invention or a

 invention

 Fluid processing system;

Fig. 8 is a schematic representation of three

 exemplary inventive pipette tips a), b) & c) with electrodes of different widths, which form a set of three distinguishable types of pipette tips; and

 Fig. 9) is a representation of a pipette tip according

 a further embodiment of the invention in three a), b) & c) different views.

In the figures, like reference numerals represent like elements.

DETAILED DESCRIPTION OF THE INVENTION

In Fig. La) is a schematic representation of a first embodiment of a pipette tip 1 with a strip-shaped volume measuring electrode 7 and a

strip-shaped immersion detection electrode 10 is shown in a sectional view from the side, while in Fig. Lb) the pipette tip 1 is shown in a view from the front (on the volume measurement electrode). The elongate tube, which forms a pipette body 4, has a substantially conical shape. The cross section of the tube may take any shape, for example, oval, rectangular, etc. The pipette body 4, however, could also be pyramidal, for example. According to the invention, the volume measuring electrode 7 is located on an outer surface of the pipette body 4 and the

Immersion detection electrode 10 on an inner surface of the pipette body 4. The immersion detection electrode 10 is shown in phantom when viewed through the material of the pipette body 4. The immersion detection electrode 10 is located within the wall of the pipette body 4 and faces the interior of the pipette body 4. Thus, the sample liquid can

 Immersion detection electrode 10 over its entire length contact, such. in Fig. La). The

Sample liquid, the immersion detection electrode but also partially, e.g. periodically

 (Contact points), contact (not shown). The immersion detection electrode 10 extends to the

Opening 5, so that they are immersed in the

 Sample liquid comes into contact with this. In contrast, the volume measuring electrode 7 should not coincide with the

Sample liquid come into contact, so that the

Volume measuring electrode 7 e.g. not to the opening 5

extends and is spaced therefrom. The

Volumenmesselektrode 7 and immersion detection electrode 10 are electrically conductive and can be arranged substantially opposite each other (this is in the Discussed in more detail below). The

 Immersion detection electrode 10 may be e.g. consist of the same material as the volume measuring electrode 7.

At its one, first end, the pipette body 4 has an opening 5 for aspirating and / or dispensing liquids. The other end is designed for fluid-tight connection to a pipette tube 2, the pipette tube 2 for example having a cone as an adapter for this purpose. The Volumenmesselektrode 7 acts as a first electrode of a measuring capacitor, which further at least a part of a recordable in the pipette tip 1

Sample liquid comprises as a counter electrode. In this case, the pipette body 4 forms the dielectric of this

Measuring capacitor. In this case, the pipette body 4 may consist of an electrically non-conductive material, which forms the dielectric, in particular a non-conductive plastic, such as non-conductive polypropylene.

The volume measuring electrode 7 is in the example shown as a narrow strip on the outer surface of the

Pipette body 4 is arranged and extends axially along the pipette tip 1 (with central axis a). The

Volume measuring electrode 7 has e.g. a width in a range of 0.8 mm to 5 mm, preferably in the range of 0.8 mm to 2 mm, particularly preferably 1 mm. At its upper end, the volume measuring electrode 7 has a

electrical contact 18, by means of which the Volumenmesselektrode 7 with the pipette tube 2 is electrically connected.

The immersion detection electrode 10 is also formed here as a narrow strip and extends axially along the pipette tip 1 (with central axis a). With the help of this immersion detection electrode 10 can be determined when the pipette tip 1, the surface of the

Sample liquid touches or penetrates and dips into it (-> "capacitive liquid level detection", cLLD). According to the invention is the

 Immersion detection electrode 10 at least partially on the inner surface of the pipette body 4 and is the interior of the pipette body 4 at least partially

exposed. In the example shown, the

 Immersion detection electrode 10 is partially embedded in the wall of the pipette body 4. Thus stands the

Immersion detection electrode 10 with the aspirated

Sample liquid at least partially in contact, whereby a more accurate determination of the volume of the aspirated

Sample liquid is made possible, especially if the sample liquid has a low conductivity. Details will be given below in connection with u.a. Fig. 6 explained in more detail.

In Fig. Lc) is a schematic representation of a second embodiment of a pipette tip 1 with a staircase-shaped Volumenmesselektrode 7 shown in a view from the front. When using such Volume measuring electrode 7 occur each capacity jumps (in the volume curve, ie the volume of

Sample liquid in the pipette tip 1 as a function of the measured capacitance), when the level of the pipette tip 1 one of the steps of the

 Volume measuring electrode 7 exceeds. Thus, e.g. the level or the volume of the sample liquid in the pipette tip 1 largely independent of the

Conductivity of the sample liquid at least roughly

can be determined, e.g. in steps of 1/4, 1/2, 3/4, 4/4 full (or even finer as in tenths). Although not recognizable, is in this embodiment, the

Immersion detection electrode disposed at least partially on the inner surface of the pipette body 4.

Figures 2a) -c) show the first and second

Embodiment and a third embodiment of the pipette tip 1 in a cross-sectional view from above. The opening 5 is in the region of the center axis of the

Pipette tip 1 is arranged. As can be seen, in FIGS. 2a) -c), the volume measuring electrode 7 is arranged on the outer surface of the pipette body 4, while the immersion detection electrode 10 at least partially forms or contacts the inner surface of the pipette body 4. The

 Immersion detection electrode 10 may be axially along the

Pipette body 4 run and in this case be strip-shaped, as shown in Fig. 2a). The

Immersion detection electrode 10 may alternatively also be arcuate and circulate the pipette body 4 to a certain inner circumference arcuate, as shown in Fig. 2b). In an example, as shown in Fig. 2b), the arcuate immersion detection electrode 10 may circulate the pipette body 4 by half of its inner circumference (180 °). In another example, the arcuate immersion detection electrode may orbit the pipette body 4 inside by three quarters of its inner circumference (270 °) (not shown). Another advantageous circulation angle is 220 °. As far as technically reasonable, are more

 Circulation angle ranges possible with which the arcuate immersion detection electrode 10 can circulate the pipette body 4 in the interior, or faces the interior of the pipette body 4.

In another example, the first electrode

contain at least two first partial electrodes 7T1,7T2 and the second electrode at least two second partial electrodes 10T1,10T2 contain, wherein the first partial electrodes

7T1,7T2 are arranged opposite to each other and the second sub-electrodes 10T1,10T2 to each other

are arranged opposite, as shown in Fig. 2c).

Fig. 2d) shows a fourth embodiment of the pipette tip 1 in a cross-sectional view from above with a coating 8 over the volume measuring electrode 7 and over the remaining pipette body 4 (i.e.

outer surface of the pipette tip 1). These

For example, coating 8 can only be used in one area Volume measuring electrode 7 may be present, for example, to prevent the volume measuring electrode 7 with the

Sample liquid comes into contact when the

Pipette tip 1 is lowered too far into the sample liquid. On the other hand, the entire pipette tip 1 may be coated with a coating 8, e.g. with a hydrophobic, oleophobic or antibacterial coating 8.

In Fig. 3a) is a schematic representation of a fourth embodiment of a pipette tip 1 with an embedded in the pipette body 4

 Volume measuring electrode 7 and a at least partially arranged on the inner surface of the pipette body 4 immersion detection electrode 10 in a sectional view from the side. The volume measuring electrode 7 is from

Inside the pipette body 4 by the material of the

Separate pipette body 4, which material as

Dielectric serves. The volume measuring electrode 7 and

Immersion detection electrode 10 are strip-shaped

formed and run axially along the pipette body 4. The immersion detection electrode 10 extends to the opening 5, while the Volumenmesselektrode 7 can extend almost to the opening 5. The same pipette tip 1 is shown in Fig. 3b) in a schematic view from above. In this case, the volume measuring electrode 7 is enveloped on all sides by the material of the pipette body 4 and enclosed therein. Again, this is the

Immersion detection electrode 10 in sections inside the pipette body 4 facing and exposed and can contact sample liquid contained therein.

Fig. 4a) illustrates in a schematic representation a use of the proposed pipette tip 1 for immersion detection (-> cLLD), i. for the determination of

Time, from when the pipette tip 1 in a

Sample liquid 6, which is located in a container 19, such. a tub, a sample tube or a "well" in a microplate, immersed (and

austaucht). The immersion detection electrode 10 is

According to the invention at least partially on the inner

Surface of the pipette body 4 arranged as

indicated schematically. As can be seen from the time course of the measured capacitance in FIG. 4b), the capacitance increases abruptly as soon as the

 Immersion detection electrode 10 touches the sample liquid 6 and immersed in this, and then drops abruptly once the immersion detection electrode 10 is pulled out of the sample liquid 6.

Fig. 5a) illustrates the use of the proposed pipette tip 1 for measuring the volume of the

Sample liquid 6, which is located in the pipette tip 1 during aspiration and dispensing. As is apparent from the time course of the measured capacitance in Fig. 5b), the capacitance increases abruptly as soon as the immersion detection electrode 10 touches the sample liquid 6 and dips into it, then increases linearly (Depending on the shape of the pipette tip 1 and the

Geometry of Volumenmesselektrode 7) due to the ever higher sample liquid column in the pipette tip 1, which forms an increasing counter electrode to Volumenmesselektrode 7 then drops linearly during dispensing and finally makes a jump down as soon as the immersion detection electrode 10 is pulled out of the sample liquid 6 ,

Fig. 6a) illustrates schematically with a sample liquid 6 'filled pipette tip 1' according to the prior art, while Fig. 6b) schematically with a

 Sample liquid 6 filled pipette tip 1 according to an embodiment of the invention represents.

Both representations assume that the

Pipette tips 1.1 'a large volume of

Sample liquid 6,6 'have recorded, with as

Sample liquid 6,6 'is assumed here a liquid with a low conductivity. It is further assumed in both cases that the

 Volume measuring electrode 7,7 'located outside the sample liquid 6,6' in the sample container or is not in contact with it.

It is known in the art that a

Immersion detection electrode 10 'on the outer surface a pipette body 4 'of the pipette tip 1' is mounted, as shown in Fig. 6a).

According to the invention, the immersion detection electrode 10 is at least partially on the inner surface of the

 Pipette body 4 attached, as shown in Fig. 6b).

Alternatively, the dip detection electrode 10 may contact the liquid column in the pipette tip 1 at regular intervals (not shown), as explained in more detail below.

Referring again to the prior art example shown in Fig. 6a), assuming a

Sample liquid 6 'having a low conductivity, the resistance within the sample liquid 6' increases with increasing sample liquid 6 'in the column

Pipette tip 1 'to, as indicated schematically by a capacitive coupled resistor series circuit (RC circuit). As the volume of the sample liquid 6 'in the pipette tip 1' increases, the capacitance increases and the resistive portion of the impedance increases - however, the capacitance and resistive component of the impedance increase unevenly, thereby changing the phase angle of the complex impedance. This will be the

Volume measurements inaccurate.

On the other hand, when the immersion detection electrode 10 is at least partially attached to the inner surface of the pipette body 4 is attached, as proposed according to the invention and shown schematically in Fig. 6b), the resistive component increases in the same mass as the capacity. Therefore, the phase angle of the complex impedance remains unchanged and the imaginary capacitive component remains dominant. This results advantageously very precise

Volume measurements. In other words, due to the

Advantageous arrangement of the immersion detection electrode 10 directly on the inner surface of the pipette body 4, the immersion detection electrode 10 is always on the same

Potential as the sample liquid 6, thereby

Advantageously, a dependence of the conductivity of the sample liquid from the volume of the sample liquid 6 in the pipette body 4 is eliminated.

FIG. 7 illustrates in a simplified schematic representation an embodiment of a

Pipetting device according to the invention. This illustration shows the pipette tube 2 with an attached

Pipette tip 1, which was previously removed from a receptacle 16 of a pipette tip holder 15 and now moved by a robot arm 14 on a liquid processing system 3 vertically upward and thus of the

Pipette tip holder 15 is removed. In this case, a capacitance measuring unit 11, which with the pipette tube 2 and thus also with the pipette tip 1 as the first electrode and the work table or the work surface 17 and thus also with the pipette tip zenhalterung 15 (or a component thereof) as the second (counter) Connected electrode is, determine the (absolute) capacity of the measuring capacitor comprising these two electrodes. Depending on the type or type (eg size / volume) of the pipette tip 1, the measured value of the capacitance will be different. For this purpose, the measured value of the capacity in one

 Detection unit 12 compared to various reference values, each reference value is characteristic of a particular type or type of

Pipette tip 1. The detection unit 12 then gives information about whether a pipette tip 1 at the

 Pipette tube 2 is connected, and if so what type or type of pipette tip 1 it is, to a control unit 13 of a drive for the robot arm 14 on. The robot arm 14 in this case has a first

horizontal movement axis (x direction, e.g., front and back), a second horizontal movement axis (y direction, e.g., left and right), and a vertical movement axis (z direction, e.g., down and up).

The Pipettenspit zenhalterung 15 can, for example, also

Part of the liquid processing system 3, wherein the robot arm 14 for determining the capacitance and thus for detecting the pipette tip zentyps or the

Pipette tip the pipette tube 2 with

connected pipette tip 1 each to

Pipette tip zenhalterung 15 moved to and

Capacitance measurement in the recording 16 lowers. Thus, the pipette tip holder 15 provides a separate / dedicated one "Measuring station" for pipette tip detection within the liquid processing system 3.

Finally, FIGS. 8a) -c) show, by way of example, three pipette tips 1 with a respective differently wide volume measuring electrode 7. The three pipette tips 1 can be a set of three

distinguishable types of pipette tips 1, which by means of the proposed recognition method based on the different capacities, which due to the different widths b _a <bb <b _{c of} the

 Volume measuring electrodes 7 result, can be distinguished from each other and recognized. Additionally or alternatively, although not shown in the figures, the respective immersion detection electrodes of the three pipette tips 1 may each have different widths, whereby the three pipette tips 1 are proposed by means of the proposed one

Detection method based on the different capacities, which result from the different widths of the immersion detection electrodes, can be distinguished from each other and recognized.

Figures 9a) -c) illustrate the pipette tip 1 according to the invention in a further embodiment. In this embodiment, the first electrode 7 is as

 Volume measuring electrode on the outer surface of the

Pipette body 4 is arranged. The first electrode 7

does not extend to the opening 5 at the front tip of the pipette body 4 (first end) and is of this opening 5 spaced. The second electrode 10 as a dip detection electrode is disposed so as to be partially on the inner surface of the

Pipette body 4 is located. Stand out for this

Contact points 20 of the second electrode 10 in such a way in the interior of the pipette body 4, that the surfaces at each distal end, for. flush with the inner

Finish the surface of the pipette body 4, e.g. in Fig. 9c). Although not shown, the surfaces at the respective distal end can not be flush with the inner surface of the pipette body 4. Other portions of the second electrode 10 extend at the

Outer surface of the pipette body 4 and can be electrically connected from there. The

Immersion detection electrode 10 orbits the pipette body 4 at a circulation angle of e.g. > 180 °, for example 220 °. Thus, it is advantageously possible that contacting points 20 are opposed to each other

may be arranged as shown in Fig. 9c). Furthermore, in each case oppositely arranged

 Contact points 20 may be arranged offset to one another. The respective opposite contacting points 20 can at a fixed offset to each other

be spaced.

The front tip of the pipette body 4 in the region of the opening 5 thereof is completely circumferential with the material of the second electrode 10 in the example shown

surround. In one example, the opening may be inside also be partially surrounded with the material of the second electrode 10. As a result, an improved immersion detection can be made possible overall. The first electrode 7 is disposed in the opening part (sector) of the partially revolving second electrode 10.

Advantageously, the second electrode 10 is centrally located therein. As shown in Fig. 9c), this is

non-conductive material of the pipette body 4 in the upper portion thereof provided with a through-hole 22, through which from the interior of the pipette body 4 from an electrical contact with the (outer) first

Electrode 7 is enabled. This allows the first

Electrode 7 are electrically connected to the pipette tube (see Fig. 7).

LIST OF REFERENCE SIGNS

1 pipette tip

2 pipette tube 3 pipetting device

4 pipette bodies

5 opening at one, first end of the pipette body

6 (sample) liquid

7 first electrode, volume measuring electrode 7T1,7T2 first partial electrodes

8 electrically insulating layer / coating (above the first electrode and the pipette body)

10 second electrode, immersion detection electrode

10T1,10T2 second sub-electrodes 11 (capacitance) measuring unit

12 detection unit

13 Control unit for controlling the movement of the drive of the pipetting robot

14 pipetting robots incl. Drive 15 pipette tip holder / carrier

16 Recording for a pipette tip

17 working table / surface

18 electrical contact 19 (sample) containers, such as a microplate with wells

20 Contact point 22 Through opening a Axis of the pipette tip b _a Electrode width ab _b Electrode width bb _c Electrode width c

x first horizontal axis of motion of the

 Pipetting robot (e.g., forward and backward) y second horizontal axis of motion of the robot

 Pipetting robot (for example, to the left and right) z vertical axis of movement of the pipetting robot

 (down and up)

Claims

1. Pipette tip (1) for connection to a  Pipette tube (2) from a pipetting device (3), wherein the pipette tip (1) is formed as an elongate tube which forms a pipette body (4) having at its one, first end an opening (5) for aspirating and / or dispensing Liquids, and at its other end for connection to the pipette tube (2) is formed, wherein the pipette tip (1) has a first electrode (7) as a volume flow electrode of a Measuring capacitor and a second electrode (10) as Immersion detection electrode, wherein the first electrode (7) is formed on an outer surface of the Pipette body (4) is or embedded in the pipette body (4) and the second electrode (10) at least partially on an inner surface of the Pipette body (4) is located. 2. pipette tip (1) according to claim 1, wherein the first electrode (7) and second electrode (10) electrically are conductive and the second electrode, the liquid on the inner surface of the pipette body at least partially galvanically contacted. 3. pipette tip (1) according to claim 1 or 2, wherein the pipette body (4) made of an electrically non-conductive material, in particular a non-conductive plastic, such as For example, non-conductive polypropylene, which acts in particular at least as part of a dielectric of the measuring capacitor. 4. pipette tip (1) according to one of the preceding  Claims, wherein the second electrode (10) is arranged substantially outside the relevant measuring capacitor. 5. pipette tip (1) according to one of claims 1 to 3, wherein the first electrode at least two first  Partial electrodes (7T1,7T2) contains and the second electrode at least two second partial electrodes (10T1,10T2), wherein the first partial electrodes (7T1,7T2) are arranged opposite to each other and the second Partial electrodes (10T1,10T2) are arranged opposite to each other. 6. Pipette tip (1) according to one of the preceding Claims, wherein the first electrode (7) is elongate, is in particular strip-shaped and extends axially along the pipette tip (1), and in particular in an angular range between 20 ° and 270 °, preferably in an angular range of 40 ° rotates. 7. pipette tip (1) according to one of claims 1 to 5, wherein the first electrode (7) is elongate, in particular strip-shaped, axially along the Pipette tip (7) runs and sections is different width, wherein the first electrode (7) in particular has a stair-step-shaped width profile in the axial direction, and the width of the first Electrode (7) e.g. at the first end is the lowest, and the width in the axial direction is gradually increased. 8. Pipette tip (1) according to one of the preceding Claims, wherein the first electrode (7) does not extend to the opening (5) at the first end and in particular is spaced from this opening (5) in a range of 3 mm to 6 mm, preferably in a range of 4 mm to 6 mm, more preferably around 5 mm. 9. Pipette tip (1) according to one of the preceding Claims, wherein the second electrode (10) is substantially strip-shaped and extends axially along the tube, and in particular up to three quarters of the Inner circumference of the pipette tip (1) rotates, continue in particular half of the inner circumference of the pipette tip (1) rotates. 10. Pipette tip (1) according to one of the preceding Claims, wherein the second electrode (10) contacts the liquid in the pipette body (4) at substantially predetermined contact points (20) along the axial direction of the pipette body (4), wherein the Contact points (20) in an angular range to each other between 90 ° and 270 °, preferably 180 °, are arranged. 11. The pipette tip (1) according to one of the preceding claims, wherein the second electrode (10) extends to the opening (5) at the first end or the opening is at least partially formed by the second electrode. 12. pipette tip (1) according to any one of the preceding claims, wherein the pipette tip (1) is a disposable pipette tip, which is provided in particular for single use. 13. Pipetting device (3) comprising at least one pipette tube (2), a pressure generating means and a measuring unit (11), wherein the pipette tube (2) at its one, first end for fluid-tight connection of a pipette tip (1) according to one of claims 1 to 11 is formed, and at the other end with the Pressure generating means is connected. 14. Pipetting device (3) according to claim 13, wherein in a region for connecting the pipette tip (1) a first electrical contact (18) for establishing an electrical connection with a first electrode (7) is provided as Volumenmesselektrode, which on an outer Surface of the pipette body (4) is located or embedded in the pipette body (4). 15. The pipetting device (3) according to claim 14, wherein the liquid is located in a sample container (19), which is electrically conductively or capacitively coupled to a conductive work table surface (17), which is connected to ground. 16. The pipetting device (3) according to claim 15, wherein the first electrical contact (7) is connected via an electrical conductor to the measuring unit (11) and the second electrical contact (10) via the liquid and a capacitive coupling of the liquid with the Worktable surface (17) with the measuring unit (11) is connected. 17. The pipetting device (3) according to claim 15 or 16, wherein the measuring unit (11) is designed to be in Dependence of a measured capacity of a Measurement capacitor, which is formed by the first electrode (7) and at least part of a sample liquid (6) accommodated in the pipette tip (1) as a counter electrode, to determine a volume of a sample liquid (6) located in the pipette tip (1), and is further configured to use the second electrode (10) immersing the pipette tip (1) in the Sample liquid (6) to detect. 18. Pipetting device (3) according to one of claims 13 to 17, further comprising a defection unit (12) for Detect if the pipette tip (1) at the first end of the  Pipette tube (2) is connected, and / or for detecting a characteristic feature of the pipette tip (1) based on a measurement of a further capacitance, wherein the further capacity is dependent on one or more of the following properties: - A material from which the pipette tip (1) consists; - A geometry of the pipette tip (1), in particular  a shape of the pipette tip (1), more particularly a diameter and / or a length of  Pipette tip (1); a coating (8) of the pipette tip (1),  in particular a material from which the coating (8) of the pipette tip (1), in particular an extension or thickness of the coating (8) of Pipette tip (1); - A material from the first and / or second  Electrode (7,10) consists; - A geometry of the first and / or second electrode (7,10). 19. Method for determining a volume of a Sample liquid (6) in a pipette tip (1) according to one of Claims 1 to 12, the method comprising the following steps: Measuring a capacitance of a measuring capacitor, comprising a first electrode (7) located on an outer electrode Surface of the pipette body (4) is or embedded in the pipette body (4), and a  Counter electrode formed by at least a portion of a sample liquid (6) located in the pipette tip (1); - Determining the volume of the sample liquid (6) in the pipette tip (1) in dependence of the measured  Capacity. 20. The method of claim 19, further comprising the step of: - Detecting a dipping the pipette tip (1) in the sample liquid (6) by means of a second  An electrode (10) as a dip detection electrode, wherein the second electrode is at least partially on an inner surface of the pipette body. 21. A method of detecting a pipette tip (1) according to any one of claims 1 to 12 on a pipetting device (3) with a pipette tube (2) at its one, first end for releasably receiving a pipette tip (1) for aspirating or dispensing a liquid (6) is formed, and which is operatively connected at its other end with a pressure generating means, wherein the Method comprises measuring a capacitance that is dependent on one or more of the following properties: - A material from which the pipette tip (1) consists; - A geometry of the pipette tip (1), in particular a shape of the pipette tip (1), in particular a diameter and / or a length of  Pipette tip (1); a coating (8) of the pipette tip (1),  in particular a material from which the coating (8) of the pipette tip (1), in particular an extension or thickness of the coating (8) of the pipette tip (1); - A material from the first and / or second  Electrode (7,10) consists; - A geometry of the first and / or second electrode (7, 10). 22. A method for producing a pipette tip (1) according to one of claims 1 to 12, comprising: Forming the pipette tip (1) as an elongate tube, which forms a pipette body (4), of a first material, - Forming a first electrode (7) from a second  Material on the pipette tip (1) on an outer surface of the pipette body (4) or in the  Embedded pipette body (4), Forming a second electrode (10) of a third material on the pipette tip (1) at least partially on an inner surface of the pipette body (4). 23. The method of claim 22, wherein the steps of molding by means of a Mehrkomponentensprit zgussverfahrens, in particular the same Mehrkomponentensprit zgussverfahrens, simultaneously with the molding of the pipette tip (1) and the first and / or second electrode (7,10) occur. 24. Use of a pipette tip (1) according to one of claims 1 to 12 for determining a volume of a Sample liquid (6), which is located in the pipette tip (1), with the aid of the first electrode (7) as  Volume measuring electrode at the pipette tip (1), wherein the first electrode (7) is located on an outer surface of the pipette body (4) or embedded in the pipette body (4). 25. Use of the pipette tip (1) according to one of Claims 1 to 12 for detecting immersion of the pipette tip (1) in the sample liquid (6) by means of the second electrode (10) as a dip detection electrode on the pipette tip (1), wherein the second electrode (10) at least partially the inner surface of the Touched pipette body (4). The set of pipette tips (1) according to any one of claims 1 to 12, comprising at least two types of Pipette tips (1), wherein the at least two types differ in that when applying the method for detecting a pipette tip (1) according to claim 21 a Capacitance of a first type of pipette tips (1) is in a first region and the capacitance of a second type of pipette tips (1) is in a second region, wherein the first and second regions are non-overlapping, and wherein the at least two types of  Pipette tips (1) in particular by one of the following features: - volume of volume; - Spit zenöffnungsgrösse / diameter for aspirating and dispensing a liquid; - with or without filter to prevent  Contaminations of the pipette tube (2) during aspiration of a sample liquid (6), and in particular a type of filter; - purity category; - Usage; - Volume measurement function; - Sealing ability of a connection of the pipette tips (1) to the pipette tube (2), and wherein in particular the outer geometry of the at least two types of pipette tips (1) may be identical.