1. Blood Types

2. Agglutinogens: Antibodies on RBC’s
Agglutinins: Antibodies floating in plasma
Blood types of A, B, AB, O are determined by the antibodies of the RBC
If an RBC has a B antibody then the plasma will have anti-A antibody to react with any unknown RBC
Clotting is a danger if the body is exposed to the same unknown RBC twice
The first time primes the response and the second triggers the clotting reaction

3. RH Factors A system based on a different set of RBC’s antibodies
There are three different genes for one trait C, D, E
If you have a trait DD or Dd you are considered RH+
Clotting also occurs after second exposure to different RH factor