Use of propidium iodide staining and flow cytometry to measure anti-mediated cytotoxicity: resolution of complement-sensitive and resistant target cells.

Propidium iodide uptake as an indicator of cell viability was used to measure antibody-mediated cytotoxicity. In conjunction with analysis using the fluorescence-activated cell sorter, this method is as sensitive as isotope release assay systems and has the advantage of gathering multiparameter data on individual cells. This feature enables the resolution of antibody-binding target cells into a population which is sensitive to complement-mediated killing and another population which is resistant to complement-mediated killing.