How platelets work
Platelets are about a quarter of the size of red blood cells and are not whole cells but rather fragile cell fragments. When a blood vessel is damaged, platelets stick to the edges of it, clustering together to plug the hole. If the injury to the vessel is large, platelets alone will not stop the bleeding, so they release other factors that start blood clotting. The interaction of the released platelet factors and other plasma protein clotting factors results in a stronger patch on the injured site.
What happens when you donate platelets?
Platelets are donated through a process called plateletpheresis, which is much more efficient than gathering platelets from whole blood donations. (A single platelet treatment would require six to eight whole blood donors instead of just one plateletpheresis donor.) It is better for the patient because it reduces exposure to multiple donors.
The platelet donation process follows the same steps as whole blood donation registration, screening, donation and after-care.
To learn more about the donation process, read the donor brochure: What you must know to donate plasma or platelets
Matching platelet donors and recipients
HLA platelet matching
Patients who receive multiple platelet transfusions sometimes produce antibodies that fight the donated platelets and prevent them from performing their clotting function. This makes ‘platelet typing’ crucial: matching not only A, O, B and AB red blood cell types but also the Human Leukocyte Antigen (HLA), which is more extensive and differentiating. Matching is about finding a donor whose platelets will be accepted readily into the recipient’s body. The odds of finding a match this close are one in four among family members and one in 10,000 among random donors.
If you’re found to be a matching donor, you could be asked to make several donations in a short period of time. Donors typically receive a few days' notice before being asked to donate but, in an emergency, we may ask you to make your special donation on short notice.
FAQs: Platelet donations
For questions related to COVID-19, see our COVID-19 page for details.
Am I eligible to donate platelets?
Any healthy individual who meets our eligibility criteria can donate platelets. Regular donors can give platelets every two weeks. Ask us about donating platelets at your next whole blood donation or give us a call at 1 888 2 DONATE (1-888-236-6283).
How often can I donate platelets?
You can donate platelets as often as every 14 days. New platelet donors are encouraged to donate once a month.
How long does a platelet donation take?
Each appointment takes approximately an hour and a half. The plateletpheresis process is usually about 75 to 100 minutes for a large-volume donation and about 50 to 75 minutes for a single-unit donation, depending on your platelet count.
What is the difference between a large-volume and single-unit donation?
Large-volume donations collect two times more platelets than a single donation. One large volume donation makes twice as much transfusable platelet units. Since our bodies manufacture and store extra platelets, the platelets collected during your donation is replaced almost immediately.
Once I start donating platelets, can I still give blood?
Yes, although we recommend you choose just one type of donation to make regularly. If you do wish to donate both blood and platelets, you need to wait 56 days after either type of donation before making the other.
What if I change my mind about donating platelets?
You’re welcome to try different donation programs to see which you like best: blood, plasma or platelets.
What if I am not eligible to donate platelets?
Every donation is valuable and helps save lives. Blood is just as important as platelets: we appreciate your generosity and commitment, whatever you’re able to give.
Where can I donate platelets?
Platelet donations are by appointment only. If you are thinking of making your first platelet donation or want to book an appointment, call your local donor centre.
Is it possible to draw only platelets from a donation?
As with a whole blood donation, we insert a needle into your arm and draw blood from your body. But instead of going straight into a collection bag, the blood passes through a centrifuge that separates out your platelets. The rest of the blood flows back into your body through the same needle. Most of the time only platelets are collected however, every 56 days we may collect plasma at the same time as the platelet donation. All of the supplies that come in contact with your blood are sterile and used only once.