Blood transfusion is something very common and this simple operation is performed in every hospital. Carl Landsteiner was the first scientist to discover that special antigens can be found on the surface of some antibodies in the plasma and erythrocytes.
Those antigens are very important when it comes to blood transfusion – in case the antigen found on the erythrocytes in the blood of the donor is the same as the antibodies in the patient’s plasma, the blood may clot and eventually cause death.
The antigens found on erythrocytes are divided in two groups “A” and “B”. The antibodies which clot the blood are also “a” and “b”. Modern medicine has determined four blood groups – A, B, AB and O. Blood can be transfused between people who share the same blood group.
A person who has the O group can give blood to anyone, but can only accept blood from donors which have O group.
On the other hand, people with the “AB” group can accept blood from anyone, but can only donate to people with “AB” group. Another important factor to take in account when talking about blood transfusion is the Rhesus factor.