The prevention of clumping of frozen-stored leukocyte populations by EDTA

Abstract The clumping of cell suspensions observed after thawing of frozen-stored leukocyte suspensions was investigated. The clumping, which was secondary to the aggregation of dead granulocytes and viable lymphocytes, could be virtually eliminated by the use of purified mononuclear cell preparations or by the addition of EDTA to media prior to freezing and during thawing.