Recovery in vivo after 51Cr labeling, platelet morphology, and platelet aggregation were studied with platelet concentrates (PC) stored for transfusion under carefully controlled conditions. PC were prepared to a final volume of 50 ml from whole blood anticoagulated with citratephosphate-dextrose (CPD). The platelet count was kept between 0.8 and 1 .6 x 1 012 platelets/liter. The PC were stored...