An isotope-release assay and terminal-labeling assay for measuring cell-mediated allograft and tumor immunity to small numbers of adherent target cells.

A 51Cr-release assay and terminal 51Cr-labeling assay for measuring cell-mediated immunity to adherent target cells is described. Both techniques utilize small 10 microliter-per well microtiter plates, require low numbers of target cells (50-500 per well), and consequently, relatively small numbers of effector cells per well (3x10(3) -1x10(5)). Both assays are objective, quantitative, and simple to perform. The suitability of these techniques for monitoring immunologically specific, cellmediated, cytotoxic response to syngeneic and allogeneic tumor cells and normal skin fibroblasts is demonstrated. Lymph node cells, spleen cells and peritoneal exudate cells serve as effectors.