title: Microcalorimetry as a tool for the detection of complement-dependent cytotoxicity.
abstract: Microcalorimetry using a 4-channel static ampoule microcalorimeter of thermopile type has been evaluated as a tool for the detection of complement-dependent cytotoxicity against the surface antigens of living cells. Cytotoxic reactions mediated by a rabbit antiserum against human white blood cells and by 2 different monoclonal antibodies recognizing a melanoma-associated antigen on a human melanoma cell line were studied. The cytotoxic reactions were registered as a decrease of the heat production rate when the cells were exposed to antibodies in the presence of active complement as compared to the heat production rate of the cells exposed to the same antibodies in the presence of inactive complement. This investigation shows that microcalorimetry can be used as a highly sensitive method for the detection of complement-dependent immune reactions, detecting antibody dilutions higher than 10(-5). It also indicates that microcalorimetry may become a particularly important technique in the analysis of the kinetics of cytotoxic immune reactions in vitro.
mesh_terms: D000818:Animals; D002151:Calorimetry / Q000379:methods; D003167:Complement Activation; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007700:Kinetics; D007962:Leukocytes / Q000276:immunology; D008545:Melanoma / Q000276:immunology; D011817:Rabbits