Platelets are the component in human blood responsible for stop bleeding from a wound. https://en.m.wikipedia.org/wiki/Platelet
Unlike whole blood donation that can be refrigerated for a few weeks, platelets are good for only a week after collection. So hospitals need a lot of this stuff to support surgery patients needs.
Another difference is how they are collected. Whereas whole blood donation drains fluid from your veins in about 30 minutes, platelet donation takes about 90 minutes. In a sterile closed system of tubes and centrifuge, the machine collects just the components they need and returns every thing else back to your body. This procedure used to require two good veins from the donor. For the last 20 years they have been able to use just one needle to do everything. It is simply amazing!
I have donated platelets since I was introduced to the idea as a freshman in college. It is so comfortable to donate at my alma mater that I have not switched to a hospital closer to my home. http://gotblood.ucla.edu/
Have you donated platelets lately? I bet you will often find the donation go by too quickly. When you are only half way through watching a movie, they have already finished bandaging your arm.
I was only halfway through the movie “the girl with the dragon tattoo” after this afternoon’s donation. Time to finish the movie on Netflix.