Kit used for detecting number of human chromosomes 21

Abstract

The invention discloses a kit used for detecting the number of human chromosomes 21. The kit comprises an amplification detection reagent, wherein the amplification detection reagent comprises a primer pair used for simultaneously amplifying specific repetitive sequences of chromosomes 21 and specific repetitive sequences of chromosomes 11, a fluorescent probe used for specifically detecting the specific repetitive sequences of the chromosomes 21 and a fluorescent probe used for specifically detecting the specific repetitive sequences of the chromosomes 11. The kit has the beneficial effects that the kit adopts a pair of primers to simultaneously amplify a pair of similar sequences between different chromosomes, thus avoiding mutual interference or other interferences caused by amplifying different sequences by different primers and ensuring the consistency of the amplification efficiency; the fluorescent probes are selectively designed in the DNA sequence sites with base difference so that the amplification volumes of two sequences can be respectively detected accurately via deltaCT values of real-time fluorescent PCR (polymerase chain reaction) of repeat segments, thus further improving the accuracy and reliability of the detection results and reducing the probability of causing false negative or false positive results.

Description

technical field [0001] The invention relates to a kit for detecting the number of human chromosome 21, which belongs to the field of molecular biology. Background technique [0002] Down syndrome (Down's syndrome), also known as trisomy 21, is the most common aneuploidy disease caused by abnormal chromosome number in humans, and the incidence rate of newborns is 1 / 600-1 / 800. The main manifestations of the children are severe congenital mental retardation and congenital malformations of various organs, and most patients cannot take care of themselves. At present, there is no effective treatment for this disease. Therefore, prenatal diagnosis to prevent the birth of children is the main method to prevent the occurrence of such diseases. For a long time, amniotic fluid cell culture and chromosomal karyotype analysis have become the classic methods of prenatal diagnosis (Caspersson T, Zech L, Johansson C, et al. Identification of human chromosomes by DNA-binding fluorescent age...

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Problems solved by technology

However, due to the use of two pairs of primers to amplify different fragments, very small changes in annealing temperature or differences in DNA quality will cause false negative or false positive results, resulting in inaccurate results (Helmy SM, Ismail S, Bassiouni R, et al.Sensitivity of DCSR3 / GAPDH ratio using quantitative real-time PCR in the rapid prenatal diagnosis for down syndrome[J].Fetal Diagn Ther,2009,25(2):220-223.)

[0005] The invention patents with the publication numbers CN100338227A and CN102086469A all disclose the method of detecting the number of chromosome 21 by designing different primers and probes for the specific sequences of different chromosomes. Changes in DNA quality or differences in DNA quality, which can cause false negative or false positive results

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