Actually, you can donate many different parts of your blood or whole blood. The whole blood is usually separated into its various parts, anyway, so when they take a pint of whole blood, they actually get a smaller amount of each part they need.

I donate platelets, or red blood cells, every time the hospital has a patient who needs my type. They evidently match more things than just blood type, as I've had them tell me I'm a three of four match so my particular platelets are preferable for the patient. Since the body makes red blood cells relatively quickly, you can donate as often as every three days (as opposed to every eight weeks for whole blood). One time, when someone's type matched mine almost exactly, I gave for that person three times in a week. The process takes about two hours, and they used to do it with two needles, one in each arm -- one outgoing, and one incoming, after the blood is spun through a centrifuge and the platelets are removed. The resulting product is kind of yellow or salmon colored, and they don't take a whole pint, but they get more than if they took the whole blood and separated it into red cells, white cells, and plasma. The incoming tube is the same color as the outgoing, only sometimes a little lighter because there is saline in the machine, and they add an anticoagulant so the blood doesn't clot before it gets back to me. Last time I went, they did it with one needle with two tubes in it, basically: one to collect, and one to return. It's nice having the use of one arm for the two hours.

I've also donated white cells. They usually give me steroids for a day or two beforehand to stimulate white cell production so they leave me with enough to protect myself after I'm done. Same process, basically, different machine.

I never get paid for it. Wouldn't even consider taking money. Don't let them reimburse me for the steroids, either.

I got into donating platelets after years of donating whole blood because I found out they could do more with it at the particular place I go, and also because about eight years ago, I wanted to put myself on the National Bone Marrow Donor Registry, and to do so, I had to go to the place I now donate platelets.

It's the one thing I can give that I know for a fact makes a difference.

Den-Kara, you could have told them you didn't meet the weight rquirement and seen if they would try anyway. My weight has fluctuated over the years above and below 115, and if I'm healthy and have enough iron in my blood, they take me anyway. Next time, give it a try.