ABO Group Blood Test

ABO is the best-known system for grouping blood types, though there are other methods. There are four major categories within the ABO group: A, B, O, and AB.

There are four ABO groups:

Group A: The surface of the red blood cells contains A antigen, and the plasma has anti-B antibody. Anti-B antibody would attack blood cells that contain B antigen.

Group B: The surface of the red blood cells contains B antigen, and the plasma has anti-A antibody. Anti-A antibody would attack blood cells that contain A antigen.

Group AB: The red blood cells have both A and B antigens, but the plasma does not contain anti-A or anti-B antibodies. Individuals with type AB can receive any ABO blood type.

Group O: The plasma contains both anti-A and anti-B antibodies, but the surface of the red blood cells does not contain any A or B antigens. Since these antigens are not present, a person with any ABO blood type can receive this type of blood.

Some red blood cells have Rh factor, also known as the RhD antigen. Rhesus grouping adds another dimension.

If the red blood cells contain the RhD antigen, they are RhD positive. If they do not, they are RhD negative.