Validation of HLA-DR locus typing in forensic specimens by combining PCR-SSP with PCR-RFLP.

The applicability of HLA-DR DNA typing combined with PCR-SSP (sequence specific primers) and PCR-RFLP (restriction fragment length polymorphism) to forensic practice was investigated. PCR-SSP was as effective as serological HLA-DR typing in determining DR types. For more precise definition of DRB1 alleles encoding DR2, DR4, and DR8 antigens, which are fairly common in Japan, we used the PCR-RFLP method. For increasing the sensitivity of this system, we used the nested or semi-nested PCR technique. The minimum amount of template DNA needed for typing was 10 ng of genomic DNA in the case of ordinary PCR, whereas 10 pg of DNA was enough in nested and semi-nested PCR. HLA-DR and-DRB1 alleles were able to be determined from the small amounts of DNA available in forensic materials using the PCR-SSP and subsequent PCR-RFLP methods.