BD Vacutainer® PST™ Tubes contain spray-coated lithium heparin and a polymer gel for plasma separation. Samples processed in these tubes are used for plasma determinations in chemistry. BD Vacutainer® PST™ Lithium Heparin Tubes eliminate the need to wait for a clot to form, making it an ideal tube for STAT procedures, as well as for patients receiving anticoagulant therapy. They provide the convenience of gel separation with the added advantage of improved turnaround time.