Platelet preservation. IV. Preparation and cryopreservation of platelet concentrates from fresh and overnight-stored human blood.

Two methods were used for the preparation of platelet concentrates from fresh and overnight-stored human ACD blood. In a two-step method prostoglandin E1 was added to platelet rich plasma and the mixture was centrifuged to obtain platelet concentrate. The IBM 2991 Blood Cell Processor was used in a one-step method. The concentrates were stored in the frozen state. Concentrates prepared with the two-step method had a higher platelet recovery and a lower leukocyte contamination than did concentrates prepared with the one-step method. Based on serotonin uptake volocity, response to hypotonic stress and available platelet factor 3, no essential differences were observed between platelet concentrates prepared from fresh and overnight-stored blood. Concentrates prepared with the one-step method had a higher serotonin uptake velocity than those prepared with the two-step method. This did not result in a better recovery after cryopreservation.