A convenient and economical freezing procedure for mononuclear cells.

Cryopreservation techniques have become essential in longitudinal evaluation of lymphocyte function. This study describes a convenient method for freezing of peripheral blood mononuclear cells, using a small cryocontainer. Analysis of cell function, assayed by lymphoproliferation to recall antigens and by cytotoxic capacity of activated lymphocytes, was performed in parallel on fresh and frozen-thawed cells. Although cryopreservation did affect lymphocyte function, our results indicate that this freezing method performed equally well compared to a computer controlled device. We conclude that the cryocontainer has proved to be a suitable and practical tool in clinical studies and is an economical alternative to conventional methods.