Serological detection of mixed lymphocyte culture identity between cells that differ by one HL-A haplotype

Antibody mediated cell dependent immune lympholysis (ABCIL), an extremely sensitive serological technique for detecting tissue sensitization, was used in a family segregation study. Two serums capable of demonstrating ABCIL were used to identify members of the family who differed by one HL-A haplotype but whose cells did not stimulate in mixed lymphocyte culture. Absorption study of one serum indicated that the ABCIL reaction of that serum was directed against a factor, independent of HL-A, that might be responsible for lymphocyte stimulation in mixed lymphocyte culture. Thus the ABCIL technique may be used to detect lymphocyte-defined gene products.