ABSTRACT
HLA-DRB1 allelic specificities can be determined using SSOs annealing to their complementary PCR-amplified target DNA. To perform HLA-DR oligotyping routinely for donors and recipients of bone marrow transplantation, a "reverse" dot-blot technique has been developed that consists in the hybridization of labeled PCR-amplified target DNA to SSOs that have been first attached to nitrocellulose membranes. The 15 oligonucleotides chosen enabled the following HLA-DRB1 "generic" specificities to be defined: DR1, BON, 2, 3, 4, 11, 11 JVM, 12, 13, 13 HAG, 14, 7, 8, 9, 10. The genomic DNA was amplified by asymetric PCR with incorporation of biotinylated deoxynucleotides predominantly to generate labeled single-stranded DNA. Hybridization between specific immobilized oligoprobes and target DNA was nonradioactively detected by a colorimetric reaction using alkaline phosphatase. The reverse dot-blot methodology was successfully tested, first, for the determination of HLA-DR4 subspecificities, and then the procedure was routinely applied to the generic HLA-DR oligotyping of bone-marrow donors and recipients.
