Blood type
There are four main Blood types; type A, type B, type AB and type O.
These relate to blood cell types and can be available in any combination in a person. Thus, a person's blood may contain both type A and B cell types. They would then be classified as type AB. Having neither of these cell types indicates type O.
Blood type is also classified through a rhesus antigen factor, also known as the Rh factor of blood. Of the four blood types in the ABO system, any can have a positive or negative Rh factor. Transfusion patients or those needing blood can receive Rh positive blood only if they are Rh positive as well; Rh negative blood can be given to either an Rh positive or negative patient. Genetically, having a positive rhesus antigen factor is a dominant trait.
Under the so-called ABO blood classification system in use for more than a century, Type O blood can be given to anyone, because it lacks such antigens. People with this blood type are known as "Universal Donors" and are much in demand by phlebotomists. But Type A blood can only be given to people whose blood is Types A or AB, and Type B blood can only be used in those with blood Types B or AB. Type AB people are known as "Universal Recipients" as they can receive blood from any other blood type as well as their own.[1]
See Also
External links
- Breakthrough makes all blood types universal - Joyce Howard Price, The Washington Times - April 4, 2007