From this study, it is clear that: 1. Most alleles of DRB1, DRB3, DRB4, DRB5, and DQB1 can be identified by 19 combinations of primers. 2. Among a total of 81 alleles, 54 of 64 were contained in the DRB1, B3, B4 and B5 loci, and all 17 DQB1-locus alleles were identified by this method. From this extensive population study and past serological experience, it is clear that: 3. SSPM, which uses only primers, not probes, is another tool that can be utilized to detect polymorphisms or microvariations in DNA sequence within the same locus.