The principle of blood group identification is to classify blood groups into four types: A, B, AB and O according to whether there is A antigen or/and B antigen on red blood cells. ABO blood group can be accurately identified by erythrocyte agglutination test and positive (serum test) and negative (cell test) typing.
The so-called positive typing is to determine whether there is corresponding A antigen or/and B antigen on red blood cells with known anti-A and anti-B typing serum, and the so-called reverse typing is to determine whether there is corresponding anti-A or anti-B antigen in serum with known A cells and B cells.
Extended data:
A person has 23 pairs (46 chromosomes), and a pair of genes in the same position of the same pair of chromosomes are called alleles, usually one from the father and one from the mother. If an allele of a DNA locus is detected, one should be the same as the mother and the other should be the same as the father.
The most basic premise is that the DNA of blood, saliva, semen and organs and tissues of the same individual is consistent and remains unchanged throughout the life of the same healthy person.
Individual high specificity: the difference of genetic essence at the molecular level of different individuals determines that the same restriction enzyme digests genomic DNA, and the number and length of allele fragments of one individual and another individual cannot be the same, thus producing individual-specific DNA.
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