Method for measuring STR site repeat frequency

Abstract

The invention relates to a STR point repetition number measuring method, which belongs to the biological technology field. The invention comprises the contents that: firstly, a 4bp repetition unit is selected, a STR point which has incomplete repetition allclomorphic gene is taken as a measuring point, and a PCR primer is designed, to ensure that the size of the product is the multiple of 4, and simultaneously is below 160bp; secondly, a DNA Ladder with the interval of 8bp is taken as the molecular weight standard; thirdly, the conventional non-denatured polyacrylamide gel electrophoresis is used to segregate the STR point. In an electropherogram, the comparison of the PCR product of the STR point and the position of the DNA Ladder fragment can accurately determine the size of the PCR product fragment of the STR point, and calculate the repetition number of the STR. The invention has the advantages that the method is simple and easy, the cost is inexpensive, and the measured accuracy is high. The invention can be used in the manufacture of a human gene ID card, and can be promoted in the repetition number measurement of the STR of other repetition units and the STR analysis of other biological materials.

Description

Technical field: [0001] The invention relates to a method for measuring the number of repetitions of STR sites, which belongs to the field of biotechnology. It is especially suitable for the production of genetic ID cards. Background technique: [0002] Short tandem repeats (short tandem repeats, STRs) are ubiquitous in the genomes of higher eukaryotes, and the same STR site is different among different individuals. This difference is called polymorphism. Due to this polymorphism It is heritable, so it is a biological characteristic of each individual organism, and it does not change with differences in development time and tissue location, so it is widely used in the identification of individual organisms. Each STR locus has several to dozens of polymorphisms. Select multiple different STR loci. The combination of polymorphisms at each locus can distinguish any two "non-identical clonal individuals", so this method can be used Technology to make genetic "fingerprints" of ...

AI Technical Summary

Problems solved by technology

This technical system can determine the number of repeats of STR, but it has the following disadvantages: 1. The equipment and reagents are expensive, and the test cost per person is nearly 800 yuan, or even higher; 2. It is difficult to increase the number of sites, because currently The types of fluorescent colors are limited, the space of each group is limited, and it is difficult to increase the number of sites. At the same time, the number of sites increases, and the difficulty of PCR amplification during the detection process increases.

The reason why the size of the PCR product cannot be determined by conventional electrophoresis method is that the PCR product of STR is relatively large, most of which are 200-400bp. When the PCR products between the two samples only differ by one repeat (3-6 bases), Conventional electrophoresis is difficult to distinguish; another problem is the need for molecular weight standards to accurately determine the size of PCR products

[0006] Through literature search, do not see the public report identical with the present invention

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