Blood Drug Testing

Wondering about blood types? agglutination? testing?

ok so we did this lab activity at school for biology but i'm a little confused and i don't understand what my teacher was trying to explain to me when i asked her.... now: we took an unknown sample of "blood" (it was a synthetic-type of blood) and we put it in 2 wells on a spot plate..... then we put 2 drops of anti-A serum in the first one... and 2 drops of anti-B serum in the second one.... the first one (anti-A) agglutinated and the second one (anti-B)didn't this means that the unknown sample is type A blood... but i don't understand why :( i know that each blood type comes with it's own antibody ex. a-type= anti-b b-type= anti-a what i was thinking was that when the blood "agglutinates" it is attacking the opposite of what it is (so if the blood type was B and you added anti-A to it it would attack it) this is why i thought this blood type was B..... just don't get why it's A? can anyone help me out? did i interpret the "agglutinating" part wrong? Louise... not to be rude... but i'm in desperate need of some help... and that was not an answer!!!!! you can figure out ur blood type by testing ur blood (ask the doctor next time you go it is probably on your record/file) Rednate OMG THANK YOU SOOOO MUCH :D that helped A LOT :D i thought that the anti-A/B was just like adding A/B blood not the opposite of it :P THANK YOU :D

Public Comments

1. i have always wondered what mine is ^^
2. If the red blood cell has the A antigen, the person is type A.If the cell has the B antigen, the person is type B. Antibodies are produced when the body recognizes a foreign antigen. So a type A person may or may not have antibodies against B antigen. Antibodies to antigen B are produced only when the person is exposed to antigen B. In your experiment, you used antibody to detect an antigen on blood cells. When you have agglutination, the result is positive on that antigen.
3. A blood has A antigens and B blood has B antigens on the surface of the erythrocytes. Blood doesn't agglutinate when more blood of the same type is added to it. It does when blood that contains antibody against its type of antigen is added. If you add anti-A, its like adding type B blood, which results in aggl. Type B blood (B Ags) will react with anti-B antibody present in type A blood.