Where Are the A & B Antigens on a Red Blood Cell?

March 4, 2011 at 8:00 am

By Billie Rubin, Hemoglobin’s Catabolic Cousin, reporting from the labs of Stanford Blood Center

Well, think of a little red blood cell (RBC) in 3D with lots of tiny little hairs sticking out of it. Type A people have about 1,000,000 of these hairs on each RBC and at the end of the hair is an A. Type B people have about 700,000 hairs with a B at the end of it. And AB people have about 600,000 hairs with A’s and 700,000 hairs with B’s at the ends. Don’t you wonder who in the world counted these hairs? Science is strange.

Then of course we have the type O’s. They just have lots of hairs with nothing at the end of them. The hairs are so tiny that you can’t see them under a microscope, but they are lurking there, believe you me…They are little chemical structures on the RBC membrane that determine the ABO type (along with the antibodies in your plasma).