Criteria to define HLA haplotype loss in human solid tumors

Short tandem repeat (STR) markers are currently used to define loss of hete rozygosity (LOH) of genes and chromosomes in tumors. Chromosome 6 and chrom osome 15 STR markers are applied to define loss of HLA and related genes (e .g. TAP and beta(2)m) The number of STR identified in the HLA region is sti ll increasing. In this study, seven representative STR markers covering the 6p/6q arms of chromosome 6 including the HLA region and two for chromosome 15 flanking the beta(2)m gene, were selected as minimally required for rel iable LOH studies. A multiplex polymerase chain reaction (PCR) strategy is proposed when small number of cells are available in microdissected tumor s amples.