Sperm Cell Capture Based on ABH Antigen Differences to Separate Two Men in Mixed Seminal Stains

Abstract

Personal identification of two individuals in mixed semen samples in forensic DNA testing in general usually involves analysis using autosomal and Y chromosome short tandem repeats (STRs). Results may exclude unrelated donors but cannot identify individuals. In this study, sperm cell capture based on ABH antigen differences was used to obtain the cells with the single ABO blood type. Immunohistochemical staining using labeled anti-A, anti-B, and anti-H antibodies and the laser microdissection system can be used to enrich sperm with different ABO types in mixed seminal stains from two individuals. Then, PCR amplification and capillary electrophoresis were performed to genotype the STR loci. To some extent, after sperm cell capture based on ABH antigen differences, autosomal STR typing using enriched single blood group cells can be utilized to partially identify different individuals in a mixed seminal stain sample from two individuals.

Separation mixed semen of two individuals using magnetic beads coupled ABH blood group antibody

“…The second step involves the qualitative movement of the antigen-antibody-magnetic beads immune complex under an external magnetic field to separate the cells [28]. Most of the ABO blood group antigens are located in the head of the sperm cells [2,14]. This means that even sperm cells that have lost their tail or have broken bodies can still be captured by magnetic beads using antibodies against ABO blood group antigens.…”

“…The male component can be obtained after the differential digestion of female constituents [1]. However, in some cases, the sperm cells of multiple male offenders are often mixed together, posing challenges in separating the male components from the large number of female epithelial cells using the traditional extraction methods [2]. Even if the typing results are obtained, analyzing the results can be complicated due to the presence of multiple mixed components or the dominance of the female component [3].…”