Functional integrity of cryopreserved human monocytes.

Human peripheral blood monocytes collected by semicontinuous flow centrifugation were cryopreserved in varying concentrations of dimethyl sulfoxide (DMSO). Optimum protection from lethal cryoinjury was achieved with 7.5-10% DMSO. Compared to fresh cells, cryopreserved cells retained 80% of their chemotactic responsiveness and fructose-6-phosphate shunt activity after stimulation by zymosan. Fresh and cryopreserved human monocytes had comparable but low levels of cytotoxic activity against P-815 murine mastocytoma cells in vitro.