To better understand the process of time-related functional deterioration which occurs in human polymorphonuclear leukocytes (PMNs), we examined the effects of in vitro storage on multiple functional parameters of human PMNs. Single-donor, phlebotomy-collected PMNs were stored at both room temperature and 37 degrees C for 24 and 48 h, then compared to fresh cells from the same donor. Similar numbers of cells were recovered from each storage condition. Cell viability decreased after 37 degrees C storage for 48 h. Cells stored at room temperature for 24 h showed significant depression of multiple functions (bactericidal activity, chemotaxis, aggregation, superoxide production, and oxygen consumption) compared to fresh cells. They contained less vitamin B12 binding protein activity than fresh cells, and by fluorescence-activated cell-sorter analysis, their forward light scatter and membrane depolarization responses were abnormal. For all parameters examined, cells stored at 37 degrees C were more abnormal than cells stored at room temperature. Stored cells from a patient with myeloperoxidase deficiency lost bactericidal and chemotactic activity after storage at 37 degrees C for 24 h, but cells from a patient with chronic granulomatous disease retained their original bactericidal and chemotactic activity after 37 degrees C storage for 24 h. Radiation, in doses used to prevent graft vs. host disease in leukocyte-transfusion recipients (2500-5000 rads) caused a significant decrease in the mean percentage of continuous flow centrifugation leukapheresis (CFCL) collected PMNs capable of reducing nitroblue tetrazolium. Human PMNs show deterioration of multiple in vitro functions when they are stored and are susceptible to damage by radiation when they are collected by CFCL.