DNA Typing for HLA-DR Using Polymerase Chain Reaction: Application to Frozen Blood

HLA-DR specificities were typed using crude DNA from frozen blood samples. Crude extracts of DNA were prepared by boiling blood samples, and a specific segment of the HLA-DRB gene was amplified in vitro by polymerase chain reaction. After blotting to nylon filters, each specificity was detected by nonradioactively (dig-1l-dUTP)-labeled oligonucleotide probes. The results agreed with serological typing. Moreover, some DR subspecificities defined by mixed lymphocyte culture (HLA-D specificities) were also typed. These methods enabled us to utilize stored blood samples from families which have been kept at -30•Ž for eight years.