is rh negative a blood type like a, o b?
What is the Rh factor? Just as there are different major blood groups, such as type A and type B, there also is an Rh factor. The Rh factor is a protein that can be present on the surface of red blood cells. Most people have the Rh factorâthey are Rh positive. Others do not have the Rh factorâthey are Rh negative.