HLA-DQA1 AND HLA-DQB1 GENOTYPING BY PCR-RFLP, HETERODUPLEX AND HOMODUPLEX ANALYSIS

PCR-RFLP typing methods for DQA1 and DQB1 in conjunction with the anal ysis of heteroduplex and homoduplex patterns have allowed a simple met hod for typing all of the major DQA1 and DQB1 alleles. This method has advantages over PCR amplification with sequence-specific primers (PCR -SSP), PCR hybridization with sequence-specific oligonucleotide probes (PCR-SSO) and other PCR-RFLP strategies for typing DQ alleles. The an alysis of heteroduplex and homoduplex patterns can be used in conjunct ion with other PCR typing systems such as PCR-SSP as a confirmatory st ep with little additional work. In addition, a PCR-RFLP strategy was d esigned for resolving the DQB10602 and DQB1*0603 alleles, which invol ved the use of a primer containing a base mutation, creating a new res triction site which distinguished the two alleles. These techniques ha ve enabled resolution of the major homozygous and heterozygous combina tions of these DQA1 and DQB1 alleles. The PCR-RFLP technique does not require the large number of oligonucleotides that are necessary for bo th the PCR-SSP and PCR-SSO techniques and is thus both time and cost e ffective for infrequent or small numbers of samples.