The measurement of cytotoxicity by the reduction of hybridoma plaque-forming cells.

Hybridoma cells secreting antibody against heterologous erythrocytes have been used as targets to measure cytotoxic T cell activity. The ability of the target cells to form hemolytic plaques has been used as an index of target viability. It has been possible to devise a sensitive plaque reduction method for measuring cytotoxicity which lends itself to screening small numbers of cytotoxic cells.