Central Blood Bank

To determine your blood type, we mix a blood sample with each of the three different antibodies, A, B and Rh.


When clumping occurs, the blood has reacted with that antibody and therefore has that antigen on the surface of its red blood cells.


Knowing which antigens are in a person’s blood makes it easy to figure out which blood group he or she belongs to.


Central Blood Bank can do this process right on-site!

A small sample of blood is taken and mixed with the three antibodies while you wait. The result comes less than a minute later and is 90 percent accurate.



  1. Blood sample is mixed with antibody A: clumping occurs
  2. Blood sample is mixed with antibody B: no clumping occurs
  3. Blood sample is mixed with the Rh antibody: clumping occurs


That person is blood type A positive

(The sample reacted with A, so it has the A antigens. It did not react with B, so it does not have the B antigens. It reacted with Rh, so it has the Rh antigens.)


This on-site typing test is not the test of record. To confirm your blood type, call 1.866.366.6771 after your donation.