Microcytotoxicity is used for -

Ans. is 'a' i.e.,Tissue typing A micro-cytotoxicity assay, utilizes serum with known anti-HLA antibodies that recognize paicular HLA loci (HLA-A, HLA-B, HLA-C, HLA-DP, HLA-DQ, HLA-DR) in order to match genetically similar individuals in hopes of performing a tissue transplantation.In this technique a donor's blood cells are MHC typed by mixing them with serum containing the anti-HLA antibodies. If the antibodies recognize their epitope on the MHC then complement activation occurs and the cell will be osmotically lysed.Another technique of tissue typing, "mixed leukocyte reaction", is performed by culturing lymphocytes from the donor together with those from the recipient. It tests cell mediated response against the tumor cells.