Abstract

In vitro morphological and functional studies were carried out on platelets which had been cryopreserved in the presence of 5% dimethyl sulphoxide (DMSO). Overall loss of platelets was around 50%. Those which survived freezing and reconstitution showed marked morphological deterioration, increase of procoagulant activity (PF3a) and a decrease in their aggregability and adenine nucleotide content. We conclude that if transfused, cryopreserved platelets are likely to be less effective than fresh platelets and may activate coagulation in vivo and that they should only be used when suitable fresh platelets are not available.