The rhesus factor, or Rh factor, is a protein that may be present on the surface of red blood cells (RBCs). If RBCs contain the Rh antigen, they are Rh-positive, and if not, they are Rh-negative. It ...
You are probably aware of the two main blood group systems: the AB system and the rhesus system. Under the AB system, there are four main blood types A, B, AB and O. And each of these four types can ...