Objective: To develop an oligoneucleotide array for HLA-DRB typing and evaluate its function in comparison with that of PCR-SSP typing.
Methods: According to the specific allele sequences of HLA-DRB loci in Han populations in Southern China, 44 synthesized typing probes were immobilized on a glass supports. A pair of group-specific primers was designed according to the sequence of HLA-DRB exon2, then the primers and Cy5-dCTP were used in PCR, thus the PCR products were labeled with Cy5. The labeled PCR products were hybridized with the probes in the array, and the signals were scanned by scanner and then analyzed by Image software.110 samples of DNA of the lymphocytes from the spleens or peripheral blood of kidney recipients and unrelated donors were typed by this array and the results were compared with those of PCR-SSP typing.
Results: All the samples except for one without PCR product had been genotyped by HLA array successfully. Ten samples were identified differently by these 2 methods. PCR-SSO verified the correctness of the array in 7 samples among which 6 samples were identified as homozygous by PCR-SSP and heterozygous by array and 1 sample was identified as heterozygous by PCR-SSP and homozygous by the array; and proved that among the remaining 3 samples the results of 2 samples identified by PCR-SSP and 1 sample identified by the array were wrong.
Conclusion: The HLA-DRB oligoneucleotide array technique is a precise, rapid molecular method for HLA-DRB genotyping. Compared with PCR-SSP method, the genotyping chip is more sensitive and specific and can test several samples at a time.