What is the basis of getting the blood type of a person?

Answer 1

The basis of getting someones blood type is to prevent an immune reaction. There are 4 human blood types: A, B, AB, and O. Each type expresses a specific antigen sequence on its membrane and the body's immune system uses this to recognize "foreign" antigens in the body. If the wrong blood type is transfused into a patient antibodies recognize the foreign antigen and an immune reaction occurs (agglutination of the foreign cells) If you have type A blood, your cells express the A antigen and there are anti-B antibodies in the circulation. Conversely, B-type has the B antigen and anti-A antibodies in the circulation. Type AB has both the A and B antigens so there is no circulating antibodies that can precipitate an immune response (this is why type AB is universal acceptor). Finally, type O has neither antigen expressed and both anti-A & B antibodies in the circulation. Because type O has no antigen on the surface it is the universal donor.

Answer 2

Antigens and Antibodies (Lock and Key)
1- Red Blood Cells have marker proteins on their surface, that makes them recognizable as a "friendly or foreign object" in the body.
2- These proteins are called Antigens and have two different shapes (Locks).
3- Plasma has another type of protein called Antibody. There are 2 different types of Antibodies (Keys).
4- Every person has one type of antigen on their RBC's and another type of antigen in their plasma (Lock and a non-matching key; like the key to your garage and the lock on your house door).
5- When 2 different blood types are mixed, they coagulate (make a clot) because the antigens from one blood type stick to the antibodies of the other blood type (matching keys open matching locks) and form a network of proteins in the blood.
6- Blood type A has antigen A on RBC and antibody B in plasma.
7- Blood type B has antigen B on RBC and antibody A in plasma.
8- Blood type O has no antigens on RBC and both antibody A and B in the plasma.
9- Blood type AB has both types of antigens on RBC and no antibody in plasma.
10- To determine a blood type, antibody of each blood type (A or B) is added to the sample of the blood.
11- Four different situations may happen:
a- If when antibody is added to the sample nothing happens, the blood type and the antibody type are not matching (ex: if antibody A is added to a blood sample and nothing happens, the blood type is the blood type is either B or O and if antibody B is added to the sample and nothing happens the blood type is either A or O)
b- if the blood clots antigen and antibody are of the same type, therefore the blood type is the same as the antibody or is AB.
e- if both types of antigens are added to the sample and nothing happens the blood type is O (you have 2 different keys but the door doesn't even have a lock).
f- if both types of antigen clot the sample the blood type is AB (you have a lock and a dead bolt on your door and you have the keys to both of them).

Answer 3

I dunno. I donate blood, so my blood type is on my donor card.