Cryopreservation of platelets isolated with the IBM 2997 blood cell separator: a rapid and simplified approach.

The equivalent of 5-7 units of platelets, isolated from a single donor with the IBM Blood Cell Processor 2997 using a dual stage separation chamber, was frozen with the cryoprotectant dimethylsulfoxide (DMSO). The DMSO-saline solution was added directly to the platelets, and the platelets were frozen in a polyvinyl chloride plastic bag by storage in a -80 degrees C mechanical freezer. Washing the thawed platelets with a phosphate-buffered sodium chloride-dextrose solution, pH of 5.0, removed about 95% of the DMSO. In vitro freeze-thaw-wash recovery was 80%, and in vivo 51Cr platelet recovery was 31%. Platelet dense body granules were well maintained after freezing, thawing, and washing. This is a safe and effective method of platelet cryopreservation which can be performed in less time than other currently used methods.