yes there is a difference in definitions here between us. we do not collect from whole blood. However one unit of plts is .55x 10^11 from one unit of whole blood. or so i thought, i stand to be corrected for definitions of unit. concentrate to me is 6 units taken off an apheresis machine. if i get 12 from one apheresis collecting thats 2 concentrates. noooooo i dont divide them up. but if i get 8 off an apheresis and due to a tight inventory, i will send an aliquote of 2 to an infant needing 2 and the remaining 6 to the adult. sorry for grammar and spelling, i just woke up and am happy i saw your replies. what is the evidence based , standard of care adult dose of plt apheresis in North America: 6 units (3 x 10^11)??