Gamma Associates proposes to produce for commercial purposes human monoclonal antibodies agaist Rh antigens on human blood cells. The project has become feasible through newly-developed methodology accessible to the company. Production strategy will entail the transformation by Epstein Barr Virus of immune B cells obtained from donors who have high anti-Rh titers as a result of Rh-incompatible pregnancy. Lymphoblastoid cell lines which produce Rh-specific antibodies will be stabilized by repeated cloning. Cloned cells will be fused to the heteromyeloma cell line DE33 or equivalent myeloma cells to provide high-secreting hybridomas. The specificity of arti-Rh antibody will be evaluated by testing on a panel of known human red blood cells as well as by segregation analysis in informative families. The purpose of this research is to collect a large set of standardized, reproducible monoclonal antibodies for diagnostic typing of the human Rh antigen system. The company anticipates that relevant antibodies will eventually be used for prophylactic desensitization of women who beer Ph-incompatible fetuses. Hybridoma-derived Rh antibodies will constitute an invaluble resource to replace the dwindiing supply of naturally-occurring Ph-immune gamma globulin.