RESUMO
The second exons of HLA-DRB genes of Chinese homozygous cell lines were amplified with polymerase chain reaction (PCR), followed by digestion of the amplified DNA segments with the allele-specific restriction endonucleases Cfo 1 and Hinf I. The resulted patterns of restriction fragment length polymorphism (PCR-RF LP) in polyacrylamide gel electrophoresis were used for HLA-DR genotyping. With advantages such as short time-consuming, accuracy and no usage of radioisotope to label oligonucleotide probes for hybridization, the technique has been proved to be capable of subtyping five Chinese HLA-DR 5 cell lines to DRw11 and DRw12 when compared with the PCR-RFLP patterns of reference cell lines. In addition, three Chinese DRw12 cell lines Showed their differences with the reference DRw12 cell BM16 in the genotyping, suggesting that the Chinese DRw12 cell lines might be categorized as new DR5 subtypes or variants related to DRw12.