A collection by leading experts detail of readily reproducible methods for identifying polymorphisms in the human MHC. Described in step-by-step detail to ensure robust and successful experimental results, these techniques provide DNA-based protocols for the study of polymorphism in HLA class I and II genes and in non-HLA HMC genes associated with human disease (TAP1, TAP 2, C2, C4, and TNF- a). The authors also describe methods for accessing HLA sequence data from electronic databases designed to catalog HLA-region genes and their alleles.