IDENTIFICATION OF APOPTOTIC AND NECROTIC HUMAN LEUKEMIC-CELLS BY FLOW-CYTOMETRY

Glucocorticoids kill human leukemic cells, CCRF-CEM.f2, by apoptosis. Cell death is preceded by DNA fragmentation into nucleosomal subunits which can be evaluated by DNA gel electrophoresis or by determining th e proportion of cleaved DNA in whole cell lysates. Hyperthermic treatm ent of CCRF-CEM.f2 cells induces necrotic cell death which is characte rized by a different DNA gel electrophoretic pattern. However, these t echniques cannot distinguish the individual contributions of both form s of death in a heterogeneous population. Therefore, we have developed a flow cytometric method that readily distinguishes apoptotic and nec rotic cells on the basis of propidium iodide staining and cellular lig ht scatter characteristics. This method can be used to analyze factors influencing the mechanisms of cell death after cytotoxic drug treatme nt. (C) 1994 Academic Press, Inc.