CN112899358A - Noninvasive prenatal fetal chromosome aneuploidy detection method and kit thereof - Google Patents
Noninvasive prenatal fetal chromosome aneuploidy detection method and kit thereof Download PDFInfo
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Abstract
The invention provides a noninvasive prenatal fetal chromosome aneuploidy detection method and a kit thereof, wherein the detection method comprises the steps of extracting fetal free DNA in peripheral blood of a pregnant woman, and amplifying the extracted fetal free DNA by using digital PCR; the primer used by the digital PCR comprises a three-dimensional structure, the reaction solution used by the digital PCR does not contain cytosine triphosphate deoxynucleotide components, the primer used by the digital PCR comprises a three-dimensional structure, the primer used by the digital PCR comprises a special nucleic acid sequence with no less than thirteen bases, and the special nucleic acid sequence only consists of adenine, guanine and thymine. The method for non-invasive prenatal fetal chromosomal aneuploidy detection provided by the invention applies a special buffer solution and a unique primer design, and adopts a digital PCR (polymerase chain reaction) technical means to detect whether the chromosomal aneuploidy exists in fetal DNA (particularly free fetal DNA in maternal peripheral blood).
Description
Technical Field
The invention belongs to the technical field of biology, and particularly relates to a noninvasive prenatal fetal chromosome aneuploidy detection method and a kit thereof.
Background
The prenatal fetal chromosome aneuploidy detection is mainly carried out by primary screening through Down's screening based on serology detection, a pregnant woman with higher risk can also adopt an amniotic fluid puncture method to obtain cells, and then adopts a cytobiology method to carry out karyotype analysis, and the process is considered as a golden standard, but because of the invasiveness, certain risks exist on intrauterine infection, premature delivery and abortion of the pregnant woman, and the wide application of the process in clinic is limited. In addition, cytogenetic diagnosis has the defects of long time consumption, high culture difficulty, incapability of detecting minor chromosome structural distortion and the like. Therefore, noninvasive prenatal diagnosis technology (NIPT) based on high-throughput sequencing is beginning to be applied clinically, and is now widely used for the trisomy screening and genetic disease detection of elderly parturients. However, the method is mainly based on high throughput sequencing (NGS platform) and statistical operations, and has the problems of high detection cost and long time consumption.
In recent years, researchers consider using a PCR method for NIPT detection, but the traditional PCR technical means are difficult to overcome the technical problems of non-specific amplification, low sensitivity and the like in the application process, so that the application range of the method is greatly limited. In order to avoid the influence of non-specific amplification on the signal-to-noise ratio and specificity of the result, the amplification weight in the existing PCR system is generally limited to 10. However, for the NIPT technique for detecting chromosomal abnormality, at least 20 or more PCR amplifications per chromosome in a single reaction system are required to ensure the accuracy of the detection result. Therefore, the current PCR technical means cannot meet the high difficulty requirement of NIPT detection.
Therefore, there is a need to provide an improved technical solution to overcome the technical problems in the prior art.
Disclosure of Invention
In order to solve the problems of the prior art, the invention provides a noninvasive prenatal fetal chromosome aneuploidy detection method and a kit thereof, which apply a special buffer solution and a unique primer design and adopt a digital PCR technical means to detect whether a chromosome aneuploidy condition exists in fetal DNA (particularly free fetal DNA in maternal peripheral blood).
The invention provides a method for non-invasively detecting chromosome aneuploidy of a prenatal fetus, which comprises the following steps:
step one, extracting free DNA of a fetus in peripheral blood of a pregnant woman;
step two, amplifying the fetal free DNA extracted in the step one by digital PCR;
wherein, the primer used in the digital PCR comprises a three-dimensional structure, the primer used in the digital PCR comprises a special nucleic acid sequence N which is not less than thirteen bases, and the special nucleic acid sequence N only consists of A, T bases and G bases;
wherein the reaction solution used for the digital PCR does not contain a cytosine triphosphate deoxynucleotide component.
In some preferred embodiments, the aforementioned detection method further comprises a third step of:
obtaining the copy number of chromosome 21, the copy number of chromosome 18 and the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman through the digital PCR treatment in the step two;
calculating the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman; calculating the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman; calculating the ratio of the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman to chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman; analyzing whether the fetus has the diseases of 21 chromosome aneuploidy, 18 chromosome aneuploidy or 13 chromosome aneuploidy by a statistical method.
By adopting the technical scheme, whether the chromosome aneuploidy condition exists in the fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means.
In some preferred embodiments, the digital PCR of step two uses at least 60 pairs of primers, while the detection of the target sequence is performed. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means. For the conventional NIPT technology for detecting chromosome abnormality, at least more than 20 PCR amplifications are required for each chromosome in a single reaction system to ensure the accuracy of the detection result. The existing PCR technical means can not meet the requirement of NIPT on high difficulty in detection; the technical scheme is adopted to well overcome the industrial problem.
In some preferred embodiments, the first non-chromosome 21 is chromosome 13 and the second non-chromosome 21 is chromosome 18. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means.
The invention provides a noninvasive prenatal fetal chromosome aneuploidy detection kit, which is characterized in that the noninvasive prenatal fetal chromosome aneuploidy detection is completed by the detection kit through digital PCR, a primer used by the detection kit comprises a special nucleic acid sequence N with no less than thirteen basic groups, and the special nucleic acid sequence N only consists of basic groups A, T and G. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means. For the conventional NIPT technology for detecting chromosome abnormality, at least more than 20 PCR amplifications are required for each chromosome in a single reaction system to ensure the accuracy of the detection result. The existing PCR technical means can not meet the requirement of NIPT on high difficulty in detection; the technical scheme can effectively overcome the industrial problem.
In some preferred embodiments, the reaction solution used in the detection kit does not contain a cytosine triphosphate deoxynucleotide component. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means. For the conventional NIPT technology for detecting chromosome abnormality, at least more than 20 PCR amplifications are required for each chromosome in a single reaction system to ensure the accuracy of the detection result. The existing PCR technical means can not meet the requirement of NIPT on high difficulty in detection; the technical scheme can effectively overcome the industrial problem.
In some preferred embodiments, the primers used in the detection kit comprise a three-dimensional structure. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means. For the conventional NIPT technology for detecting chromosome abnormality, at least more than 20 PCR amplifications are required for each chromosome in a single reaction system to ensure the accuracy of the detection result. The existing PCR technical means can not meet the requirement of NIPT on high difficulty in detection; the technical scheme can effectively overcome the industrial problem.
In some preferred embodiments, the detection kit employs at least 60 pairs of primers, while simultaneously performing detection of the target sequence. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique super-multiplex primer design and using a digital PCR technical means. For the conventional NIPT technology for detecting chromosome abnormality, at least more than 20 PCR amplifications are required for each chromosome in a single reaction system to ensure the accuracy of the detection result. The existing PCR technical means can not meet the requirement of NIPT on high difficulty in detection; the technical scheme can effectively overcome the industrial problem.
In some preferred embodiments, the test kit further comprises a treatment method using:
acquiring the copy number of chromosome 21 and the copy number of a reference chromosome of fetal free DNA in the peripheral blood of the pregnant woman by a digital PCR (polymerase chain reaction) technical means; the copy number of the reference chromosome is the copy number of chromosome 13 of the fetus in the peripheral blood of the pregnant woman and the copy number of chromosome 18 of the fetus in the peripheral blood of the pregnant woman;
calculating the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman, the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman, and the ratio of the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman.
By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique primer design and using a digital PCR technical means.
In some preferred embodiments, the digital PCR uses at least 60 pairs of primers, while performing the detection of the target sequence. By adopting the technical scheme, whether chromosome aneuploidy exists in fetal DNA is detected by adopting a special buffer solution and a unique super-multiplex primer design and using a digital PCR technical means. For the conventional NIPT technology for detecting chromosome abnormality, at least more than 20 PCR amplifications are required for each chromosome in a single reaction system to ensure the accuracy of the detection result. The existing PCR technical means can not meet the requirement of NIPT on high difficulty in detection; the technical scheme can effectively overcome the industrial problem.
In some preferred embodiments, the detection kit is used for noninvasive detection of prenatal fetal chromosomal aneuploidy.
The beneficial effects created by the invention are as follows:
the invention provides a noninvasive prenatal fetal chromosome aneuploidy detection method and a kit thereof, which apply special buffer solution and unique primer design and adopt a digital PCR technical means to detect whether chromosome aneuploidy exists in fetal DNA (free fetal DNA in maternal peripheral blood).
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In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to these drawings without inventive effort.
FIG. 1 shows the application of the method described in example 1 to 269 clinical specimens tested; wherein neg is the z score value of a healthy fetal sample, and T21 is the z score value of a sample with a triploid abnormality of chromosome 21;
FIG. 2 is a graph showing the results of a digital PCR reaction carried out by the detection method of example 1;
FIG. 3 is a schematic diagram of the structure of the primer partial sequence used in example 1.
Detailed Description
The experimental methods of the following examples, which are not specified under specific conditions, are generally determined according to national standards. If there is no corresponding national standard, it is carried out according to the usual international standards, to the conventional conditions or to the conditions recommended by the manufacturer.
The features mentioned with reference to the invention or the features mentioned with reference to the embodiments can be combined. All the features disclosed in this specification may be combined in any combination, and each feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless expressly stated otherwise, the features disclosed are merely generic examples of equivalent or similar features.
In the present invention, all the technical features mentioned herein and preferred features may be combined with each other to form a new technical solution, if not specifically stated.
In the present invention, the term fetal DNA as used herein specifically refers to free fetal DNA in the peripheral blood of the mother, unless otherwise specified.
In order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments, but the invention includes but is not limited to the embodiments.
Example 1. A method for noninvasive detection of prenatal fetal chromosomal aneuploidy
This example describes a method for noninvasive prenatal fetal chromosomal aneuploidy detection. The detection method comprises the following processing steps:
1. sample processing
Peripheral blood samples were centrifuged at 1600g for 10 min at 4 ℃ and plasma fractions were centrifuged at 16000g for 10 min at 4 ℃ to further remove residual blood cells.
2. DNA extraction
Free DNA was extracted from plasma using the QIAamp circulating nucleic Acid extraction kit (manufacturer: QIAGEN; catalog No.: 55114) according to the manufacturer's instructions.
3. Preparing a reagent:
digital PCR reaction solutions (1 reaction) were prepared according to the recipe in table 1:
TABLE 1 digital PCR reaction solution
| Components | Volume of |
| 10×dPCR Buffer | 3.5μL |
| Enzyme | 1.0μL |
| Primer and method for producing the same | 2.8μL |
| Detection template | 1.0～17.5μL |
| Total volume | Supplementing 30-35 μ L with ribozyme-free water |
And (3) uniformly mixing the reaction solution, uniformly mixing the reaction solution by vortex for 30 seconds, and collecting the reaction solution on the bottom of the tube by instantaneous centrifugation and then placing the reaction solution on ice for later use. Among them, 10 XDPCR Buffer does not contain cytosine triphosphate deoxynucleotide (dCTP).
4. An oil phase mixture was prepared according to the formulation of table 2 (1 reaction):
TABLE 2 digital PCR reaction solution
| Volume of | |
| Oil phase A | 30μL |
| Oil phase B | 10μL |
| Total of | 40μL |
After mixing the reaction oil phases according to the formulation of table 2, vortex and mix them evenly for 30s, remove air bubbles by instantaneous centrifugation, and collect the liquid at the bottom of the tube and put it on ice for use.
5. Detection sample introduction
(1) Detection system
This example uses the U.S. Bio-rad digital PCR system with 2 fluorescent channels, using a 96-well plate with 8 reaction wells per sample, and an effective number of 2 thousands of droplets per well reaction system. 12 samples can be processed in parallel at a single time.
Designing 60 PCR primers covering the target gene locus as shown in Table 1; the templates for amplification are chromosome 13, 18 and 21.
TABLE 1 primer Probe sequences for chromosomal aneuploidy detection
The nucleotide sequence "CCTGGGGGAGTATTGCGGAGGAAGG (SEQ ID NO. 181)" was added to the 5' -end of the designed primer to obtain an initial nucleotide sequence for amplification. The primers for amplification designed for chromosome 13, 18 and 21 as described aboveThe original nucleotide sequence is sent to the company of biological engineering (Shanghai) and Limited for synthesis, the synthesized nucleotide needs to be pretreated, and the pretreatment method comprises the following steps: adding the synthesized nucleotide sequence into a buffer solution B, heating to 70 ℃, preserving heat for 5 minutes, then cooling to 30 ℃, preserving heat for 25 minutes, and obtaining the full length of the nucleotide sequence for detection; wherein, the buffer solution B comprises the following components: 300mM NaC1,5mM MgC12,20mM Tris(pH 7.6)。
(2) Sample introduction operation
And carrying out sample injection operation according to the requirements of the digital PCR sample injection instrument using operation instructions.
6. Thermal cycling reactions
The 96-well plate was placed in a nucleic acid amplification apparatus and subjected to a thermal cycling reaction.
Reaction procedure:
TABLE 3 digital PCR reaction procedure
7. Droplet read analysis
After the thermal cycle reaction is finished, the sample is moved to a biological reader for reading analysis to obtain the copy number of each fluorescence channel, namely the copy number of the No. 21 chromosome of the sample to be detected and the copy number of the reference chromosome (the No. 13 chromosome and the No.18 chromosome) are respectively obtained; wherein the copy number of the reference chromosome is an average value of the copy number of chromosome 13 and the copy number of chromosome 18 of the sample to be tested.
And calculating the copy number of the chromosome 21 of the sample to be detected as the percentage of the copy number of the reference chromosome of the sample. Similarly, the copy number of the negative sample is calculated as a percentage of the copy number of the reference chromosome of the sample.
Then, Z score (V) of No. 21 of the sample to be measured was calculatedchro.21)：
Wherein, C0An average of the copy number of chromosome 21 of the negative sample as a percentage of the copy number of the reference chromosome of the sample; c21The copy number of the No. 21 chromosome of the sample to be tested is the percentage of the copy number of the reference chromosome of the sample, sigmacStandard deviation of the copy number of chromosome 21 of the trisomy syndrome negative sample as a percentage of the copy number b of the reference chromosome of the sample;
and judging whether the number of the chromosome 21 of the sample to be detected is abnormal or not according to the Z score value of the chromosome 21 of the sample to be detected.
8. Determination of results
And (3) judging a negative sample: when the Z score of the chromosome 21 is less than or equal to 1.96, the chromosome 21 of the detection sample has no significant difference from the normal chromosome 21 in the reference sample library, namely the number of the chromosome 21 is normal;
judging a gray area sample: when the Z score of chromosome 21 falls in the range of gray zone (1.96, 3), because the possibility of false negative caused by too low fetal DNA concentration (< 4%) cannot be eliminated, the re-examination after re-blood sampling is recommended, and the re-examination result is still in the gray zone and is judged to be positive;
and (3) judging a positive sample: when Z score > 3 of chromosome 21, it indicates that there is a significant difference between chromosome 21 of the test sample and normal chromosomes in the reference database, i.e., there is an abnormality in the number of chromosomes 21 of the test sample.
The method of this example was applied to the detection of 269 clinical samples to obtain statistical results as shown in FIG. 1 (FIG. 2 is a schematic diagram of digital PCR detection results of one sample, and the results of other samples are similar to those of FIG. 2). As can be seen from the experimental data shown in fig. 1, the value of the positive test result is significantly higher than that of the negative sample, and the two sets of data can be distinguished very well. The method and the corresponding detection kit of the embodiment are proved to be capable of accurately and high-resolution identifying the chromosome aneuploid patient. The detection result is compared with the clinical blood NGS detection result, and the consistency rate is 100%.
Embodiment 2. a noninvasive detection method for prenatal fetal chromosome aneuploidy
This example describes a method for noninvasive prenatal fetal chromosomal aneuploidy detection. The difference from example 1 is that, in addition to the primer sequence adopted in example 1, a double primer is added, and the method for designing the new primer is mainly to replace all CCTGGGGGAGTATTGCGGAGGAAGG (SEQ ID NO.181) contained in all primer sequences of example 1 with ACTCATCTGTGAGACTCACTATAGGAAGAGATGTCAACTCGTGCACGAGTTGACATCTCTTCTCCGAGCCGGTCGAAATATTGGAGGAAGCTCGAGCTGGAGGAAAAGTGAGTCTCACAGATGAGT (SEQ ID NO.182), and the rest processing parameters are the same as those of example 1.
The method is applied to detection of 269 clinical samples, and the experimental result shows that the value of the positive detection result is significantly higher than that of the negative sample, and two groups of data can be distinguished very well and are better than the experimental result of example 1. The method and the corresponding detection kit of the embodiment are proved to be capable of accurately and high-resolution identifying the chromosome aneuploid patient. The detection result is compared with the clinical blood NGS detection result, and the consistency rate is 100%.
Further, the inventors mixed the primers used in this example with the primers used in example 1, and repeated the experiment described in example 1 to obtain similar experimental results; further shows that the noninvasive prenatal fetal chromosome aneuploidy detection method provided by the invention can effectively solve the industrial problem of the ultra-multiplex digital PCR amplification detection of fetal chromosome aneuploidy in the industry.
Example 3. a method for noninvasive detection of prenatal fetal chromosomal aneuploidy
This example describes a method for noninvasive prenatal fetal chromosomal aneuploidy detection. The difference from example 1 is that, in addition to the primer sequence adopted in example 1, a double primer is added, and the method for designing the new primer is mainly to replace all CCTGGGGGAGTATTGCGGAGGAAGG (SEQ ID NO.181) contained in all primer sequences of example 1 with GGGUUGGGAAGAAACUGUGGCACUUCGGUGCCAGCAACCC (SEQ ID NO.183), and the rest of the processing parameters are the same as those of example 1. The method is applied to detection of 269 clinical samples, and the experimental result shows that the value of the positive detection result is significantly higher than that of the negative sample, and two groups of data can be distinguished very well and are better than the experimental result of example 1. The method and the corresponding detection kit of the embodiment are proved to be capable of accurately and high-resolution identifying the chromosome aneuploid patient. The detection result is compared with the clinical blood NGS detection result, and the consistency rate is 100%.
Further, the inventors determined the structure of the nucleotide partial sequence of each of the primers used in examples 1 to 3 by X single crystal diffraction experiments, and obtained different three-dimensional structures required for the experiments, wherein the structure of the partial sequence of the primer used in example 1 is shown in fig. 3, and accurately completed the noninvasive prenatal fetal chromosomal aneuploidy detection required in examples 1 to 3.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. A method for non-invasive detection of prenatal fetal chromosomal aneuploidies, the method comprising:
step one, extracting free DNA of a fetus in peripheral blood of a pregnant woman;
step two, amplifying the fetal free DNA extracted in the step one by digital PCR;
wherein the reaction solution used in the digital PCR does not contain cytosine triphosphate deoxynucleotide components, the primer used in the digital PCR contains a three-dimensional structure, the primer used in the digital PCR contains a special nucleic acid sequence of not less than thirteen bases, and the special nucleic acid sequence only consists of adenine, guanine and thymine;
and step three, acquiring the copy number of chromosome 21, the copy number of chromosome 18 and the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman through the amplification of the digital PCR in the step two.
2. The detection method according to claim 1, further comprising: calculating the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman, the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman, and the ratio of the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman.
3. The method of claim 2, wherein the digital PCR of step two is performed in the same reaction system using at least 60 pairs of primers to simultaneously detect the target gene.
4. A noninvasive prenatal fetal chromosome aneuploidy detection kit is characterized in that noninvasive prenatal fetal chromosome aneuploidy detection is completed through digital PCR by the detection kit, a primer used by the detection kit comprises a special nucleic acid sequence N with not less than thirteen basic groups, and the special nucleic acid sequence N only consists of basic groups A, T and G.
5. The detection kit according to claim 4, wherein the reaction solution used in the detection kit does not contain a cytosine triphosphate deoxynucleotide component.
6. The detection kit according to claim 4, wherein the primers used in the detection kit comprise a three-dimensional structure.
7. The detection kit according to claim 4, wherein the detection kit simultaneously detects the target sequence using at least 60 pairs of primers.
8. The test kit according to claim 4, wherein the test kit further comprises the following processing methods:
acquiring the copy number of chromosome 21 and the copy number of a reference chromosome of fetal free DNA in the peripheral blood of the pregnant woman by a digital PCR (polymerase chain reaction) technical means; the copy number of the reference chromosome is the copy number of chromosome 13 of the fetus in the peripheral blood of the pregnant woman and the copy number of chromosome 18 of the fetus in the peripheral blood of the pregnant woman;
calculating the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman, the ratio of the copy number of chromosome 21 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman, and the ratio of the copy number of chromosome 18 of the fetal free DNA in the peripheral blood of the pregnant woman to the copy number of chromosome 13 of the fetal free DNA in the peripheral blood of the pregnant woman.
9. The test kit of claim 8, wherein the digital PCR uses at least 60 pairs of primers and simultaneously detects the target sequence.
10. Use of the test kit according to any one of claims 4 to 9 for the non-invasive detection of prenatal fetal chromosomal aneuploidies.
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| CN117402961A (en) * | 2023-12-13 | 2024-01-16 | 北京华宇亿康生物工程技术有限公司 | Primer, kit and method for rapidly detecting chromosome aneuploidy before embryo implantation |
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