Lack of conformity in the behaviour of platelets during normal storage conditions at 22 degrees C.

Platelets prepared from citrate-phosphate-dextrose blood under normal routine conditions and concentrated to 1,000-1,600 x 10(9) x 1(-1) varied considerably in their capacity to acidify the medium. Serotonin uptake was well maintained for 5 days provided that adenosine 5'-triphosphate was within 50% of normal and pH was above 6.0. A strong release of platelet factor 4 was occasionally seen in relation to preparation. In some preparations the platelet factor 4 was well maintained for 5 days, in others a sudden or gradual release was seen during storage. The investigation indicates that differences in the quality of routinely prepared platelets occur during preparation and storage which are insufficiently well explained and controlled.