Please help me with blood transfusions :(

You've completely misunderstood what's going on here.

You make antibodies against antigens that you don't have.

So if someone has type O blood, they'll make antibodies against antigens A and B. Therefore if you were to give someone with type O a transfusion from someone with type A, B or AB, those transfused red blood cells would be destroyed by the host (Mr/Miss type O) immune system. However, because type O has no antigens, it can be given to any of the others, hence the term universal donor.

If someone has type AB, it means they won't make antibodies against any of the antigens, because their immune system is tolerant. If it wasn't, the host's immune system would destroy its own red blood cells. This means that they can receive blood from A, B, AB and O, hence the term universal recipient.

But O has both antibodies? So won't the A antibody react with the A antigen in A?

When blood is donated, it's separated so only the red blood cells are given, not containing serum antibody.

Pleeeease can someone explain how AB is a universal recipient even though it has antigen A and B which would react with the A antibodies in B and O?

But O has both antibodies? So won't the A antibody react with the A antigen in A?

Ah, I see what you've done

Yes O does have both antibodies; as the other poster said, that's why it will reject A, B or AB blood that is transfused into it. (O also has no antigens, though.)

But the antibodies are in NOT 'carried away with the blood', as it were - they are part of the body. It's antigens that go 'with the blood', if you see what I mean. So when O is transfused to someone with type A blood, to use your example, there will be no reaction because O has NO ANTIGENS to react with the type A blood's ANTIBODIES.

So basically, it's the antigens from the 'host' blood that react with the antibodies from the transfused blood, not the other way around as you thought - that's why you were confused so type O antiBODIES don't have any effect on type A blood because it's antiGENS that react with blood and agglutinise it.

I hope that that made sense and helped you out :s are you doing GCSE Bio OCR Gateway science B, B4-6 tomorrow? Bc I am and have also been revising this


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Also how is O a universal donor if it too has antigens A and B which can react with antibody A in A and antibody B in B???? Pleeeeaae help thanks!!

This isn't strictly true. A person with type O blood has A and B antibodies in their blood, but these are seperated out via centrifuging. When red blood cells are given to a person, it doesn't need to be considered what antibodies their donor had, because they are not present. However, if plasma is given, that needs to be considered, because antibodies are present in plasma.

Ah, I see what you've done

Yes O does have both antibodies; as the other poster said, that's why it will reject A, B or AB blood that is transfused into it. (O also has no antigens, though.)

But the antibodies are in NOT 'carried away with the blood', as it were - they are part of the body. It's antigens that go 'with the blood', if you see what I mean. So when O is transfused to someone with type A blood, to use your example, there will be no reaction because O has NO ANTIGENS to react with the type A blood's ANTIBODIES.

So basically, it's the antigens from the 'host' blood that react with the antibodies from the transfused blood, not the other way around as you thought - that's why you were confused so type O antiBODIES don't have any effect on type A blood because it's antiGENS that react with blood and agglutinise it.

I hope that that made sense and helped you out :s are you doing GCSE Bio OCR Gateway science B, B4-6 tomorrow? Bc I am and have also been revising this


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Thankyou!! And yup hahaha I am :P good luck!!!