The Sound of Science - 'ABO Blood Typing'
Newt: You're listening to The Sound of Science on WNIJ. I'm Newt with NIU STEAM.
Becky: And I'm Becky. Today we want to talk about something you may know of in passing, but might not know the science behind: blood typing.
Newt: Determining what kind of blood someone has is reliant on something called antigens. In simple terms, it's like an alarm system that only sounds when the body encounters a specific foreign substance. After the alarm goes off, the body creates antibodies to combat the substance. In the case of red blood cells, these antigens live on the outer membrane of the cell forming a chain of protective carbohydrates. Blood typing has two kinds of antigens, sugars and proteins.
Becky: We've all probably heard of blood types A, B, AB, and O. This typing is based on a sugar antigen. Basically, everyone has a sort of sugar based armor around their red blood cells. People with O type blood have a common set of sugar shared across all blood types.
Newt: But types A and B each add a different sugar to the end of their chains. That extra sugar is like the difference between a square and a triangle, and both type A and type B react to the others sugar like the feuding families and Romeo and Juliet. Their mere presence is offensive.
Becky: What this means is that if someone with type A blood receives a transfusion of type B blood, their body thinks that the blood is a foreign invader trying to hurt the body. That person's immune system jumps into action to destroy the threat, which isn't very nice when the blood transfusion was likely a life saving measure in the first place.
Newt: Type AB blood has both those extra sugars, you can give someone with this blood type or any of the others. The other end of the spectrum is type O which doesn't have any of the extra sugars. It can give blood to others, but any hint of extra sugar will cause the negative reaction.
Becky: So knowing your blood type is extremely important to a doctor. If you don't know yours, you can usually find out by donating your blood or plasma. On our next episode, we'll be talking about the other antigen present in the blood that adds an extra layer to your blood type. But for now...
Newt: This has been The Sound of Science on WNIJ, where you learn something new every day