Most membrane-surface antigens which are exposed to the surface of a cell display a number of epitopes or antigenic determinants.Allo-antigens possess unique epitopes peculiar to their haplotype(private specificities)but they my share epitopeswith antigen of other haplotypes (public specificities) Each haplotype of an inbred strain produces antigens which can stimulate an immune response in strains possessing a haplotype lacking that antigen or unique epitopes within that antigen.This can be exploited as a diagnostic or analytical tool. Monoclonal antibodies for a single epitope can be produced.A panel of different onclon antibodies can be developed that permits serological tissue typing.The antibodies can be used to identify a wide range of class I MHC determinants.Class II antigens can be detected by measuring their ability to stimulate allogeneic lymphocyte to divide in a mixed lymphocyte culture. Typing of HLA cigmphocyte Mononuclear Sti cells cells lator Collect Collect Coculture Add H-thimidine Incubate recognized as foreign cognized as foreign no increas in H-thymidine H-thymidine in DNA DNA increasedMost membrane-surface antigens which are exposed to the surface of a cell display a number of epitopes or antigenic determinants. Allo-antigens possess unique epitopes peculiar to their haplotype (private specificities), but they may share epitopes with antigen of other haplotypes (public specificities). Each haplotype of an inbred strain produces antigens which can stimulate an immune response in strains possessing a haplotype lacking that antigen or unique epitopes within that antigen. This can be exploited as a diagnostic or analytical tool. Monoclonal antibodies for a single epitope can be produced. A panel of different monoclonal antibodies can be developed that permits serological tissue typing. These antibodies can be used to identify a wide range of class I MHC determinants. Class II antigens can be detected by measuring their ability to stimulate allogeneic lymphocyte to divide in a mixed lymphocyte culture