How Blood and Platelets Are Separated

When you give whole blood, you are actually giving several lifesaving components including red blood cells, platelets and plasma. After a whole blood donation, your blood is sent to the laboratory where it’s spun down and separated into different parts. Each part, red blood cells, platelets and plasma, has unique medical uses, storage conditions and shelf life.

Separating Platelets from a Whole Blood Donation

To separate platelets from a whole blood donation, the blood is kept at room temperature, processed and stored, all within eight hours of your donation. In order to have enough platelets for a transfusion, four to six bags of whole blood from different donors must be pooled together to make one unit of platelets. 

Platelets must be used within 5 days of donation. Platelets help stop bleeding in patients undergoing surgery or cancer patients who, due to the side effects of chemotherapy or radiation, need them to prevent hemorrhaging.

Automated Platelet Donation

During a platelet donation, called apheresis, your whole blood is removed into sterile tubing and satellite bags. A machine called a centrifuge spins your blood to separate your red blood cells, platelets and plasma. As the blood is separated, the heavier reds cells sink to the bottom and are given back to you.

The liquid plasma rises and in between these two components is a layer of platelets that are tracked into a small pouch wrapped around the cylinder of the centrifuge. When you give blood, it triggers your spleen to flood your blood stream with stored platelets to try and stop the bleeding.

Thus, more plasma and platelets are collected and you are able to donate one, two or potentially three doses of platelets during one visit.  Meanwhile, your healthy bone marrow immediately begins converting more stem cells into platelets to replace those that have been donated.

Platelet donors can give a larger quantity and, since the donation comes from a single donor, better quality of platelets to help patients in their battle to live.

Platelet donations are given primarily in the donor centers. You can donate platelets every 7 days up to 24 times a year.