Method for separating sperm cells of male individual from mixed spots by coupling magnetic bead with ABO blood group antibody

Abstract

The invention relates to a method for separating sperm cells of a male individual from mixed spots by coupling a magnetic bead with an ABO blood group antibody. A sperm cell surface specific expression ABO antigen is used for separating and recognizing the male individual. The method comprises the following steps: step 1, according to a principle of agreement of informed conditions, mixing semen of different blood types in pairs, and then mixing the mixed semen with vaginal fluid of a female individual; step 2, biotin labeling of the ABO blood group antibody; step 3, coupling sperms by using a biotin-labeled ABO antibody, and enriching and collecting sperm cells of the individual male by using avidin-coupled magnetic beads and an external magnetic field; and step 4, carrying out PCR amplification and capillary electrophoresis so as to carry out genotyping on the STR gene loci. The method can effectively determine the inference of the individual source of the male in the sperm-yin mixed plaques from the gene level, greatly simplifies the steps of recognizing the tissue source of the body fluid or the plaques in the criminal investigation scene, and can provide an accurate scientific basis for determining case properties, determining criminal suspects, determining crimes and sentencing and the like.

Description

technical field [0001] The invention belongs to the technical field of forensic medicine, and relates to a method for separating cells by immunomagnetic beads, in particular to a method for separating male individual sperm cells in mixed plaques by coupling magnetic beads with ABO blood type antibodies. Background technique [0002] The most common mixed samples are women’s vaginas or semen spots left on underwear and bed sheets in rape cases. After digesting the female components, a single male type can be obtained. However, in some gang rape cases, the semen of multiple male individuals is often mixed together, and because the male sperm is mixed with a large number of female epithelial cells, it is very difficult to separate and test the male substance by conventional methods, sometimes even if the typing results are obtained , it often shows that the types of the mixed components coexist with each other, or the female component is dominantly amplified, which makes the an...

AI Technical Summary

Problems solved by technology

Therefore, it is often only possible to exclude, but not to identify suspect individuals

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