Cryopreservation of lymphocytes to standardize in vitro immune functions

The responses of fresh and frozen lymphocytes to mitogens and antigens have been compared with the use of samples collected on five occasions from 1 normal donor. The day-to-day variation seen with the fresh cells was eliminated by the use of frozen cells. Thawed cells from 1 donor, collected once but studied on five occasions and compared with fresh cells on the same days, fluctuated from day to day as well, confirming that the day-to-day variation seen is due to technical and not biologic phenomena. Cryopreserved cells showed a decrease in responses to specific microbial antigens, a slight shift in the PHA dose-response curve, but no significant difference in responses to Con A or PWM. The relative proportion of lymphocyte subpopulations changed with freezing and thawing. The proportion of T- and B-cells increased and decreased, respectively.