About Blood Donation

  Blood Type Chart: Facts and Information on Blood Group Types


 Information regarding blood types including charts showing donor compatibility, and a child's likely blood group depending on their parents blood type.

When a person's blood is analyzed under a microscope distinct blood differences are visible. In the early 20th century, an Austrian scientist named Karl Landsteiner classified blood according to those differences. Landsteiner observed two distinct chemical molecules present on the surface of the red blood cells. He labeled one molecule "A" and the other molecule "B." If the red blood cell had only "A" molecules on it, that blood was called type A. If the red blood cell had only "B" molecules on it, that blood was called type B. If the red blood cell had a mixture of both molecules, that blood was called type AB. If the red blood cell had neither molecule, that blood was called type O.


Blood Type Facts:


There are eight different common blood types, which are determined by the presence or absence of certain antigens, which are substances that can trigger an immune response if they are foreign to the human body. Since some antigens can trigger a patient's immune system to attack the transfused blood, safe blood transfusions depend on careful blood typing and cross-matching.

There are 4 major blood groups determined by the presence or absence of two antigens (A and B) on the surface of red blood cells:


Blood Group






Has only A antigen on red cells (and B antibody in the plasma)




Has only B antigen on red cells (and A antibody in the plasma)




Has both A and B antigens on red cells (but neither A nor B antibody in the plasma)




Has neither A nor B antigens on red cells (but both A and B antibody are in the plasma)


In addition to the A and B antigens, there is a third antigen called the Rh factor, which can be either present (+) or absent ( – ). In general, Rh negative blood is given to Rh-negative patients, and Rh positive blood or Rh negative blood may be given to Rh positive patients.

-The universal red cell donor has Type O negative blood type.

-The universal plasma donor has Type AB positive blood type.


Donating Blood by Compatible Type:

Blood types are very important when a blood transfusion is necessary. In a blood transfusion, a patient must receive a blood type compatible with his or her own blood type. If the blood types are not compatible, red blood cells will clump together, making clots that can block blood vessels and cause death.

If two different blood types are mixed together, the blood cells may begin to clump together in the blood vessels, causing a potentially fatal situation. Therefore, it is important that blood types be matched before blood transfusions take place. In an emergency, type O blood can be given because it is most likely to be accepted by all blood types. However, there is still a risk involved.



Blood Type


Donate Blood To


Receive Blood From




A+ AB+


A+ A- O+ O-




O+ A+ B+ AB+


O+ O-




B+ AB+


B+ B- O+ O-










A+ A- AB+ AB-


A- O-










B+ B- AB+ AB-


B- O-






AB- A- B- O-