Question

A person with unknown blood group has suffered much blood loss in an accident and needs an immediate blood transfusion. His friend who has a valid certificate of his own blood type offers for blood donation without delay. What would have been the type of blood group of the donor friend?

Answer 1

According to distribution of antigens and antibodies there are four groups of blood, A, B, AB and O. During the blood transfusion, any blood cannot be used: the blood of a donor has to be carefully matched with the blood of a recipient before any blood transfusion to avoid severe problems. Group "O" can be donated to persons with any other blood group and hence "O" group individuals are called "universal donors". So, blood group of donor friend would be "O".