After donating blood a certain set of standard tests are performed in the laboratory, including but not limited to the following:

1. Typing: ABO Group (Blood Type)
2. Rh typing (antigen positive or negative)
3. Checking for any unexpected red blood cell antibodies that could cause problems in the recipient
4. Checking for current or past infections, including:
5. Hepatitis Virus B and C
6. Human immunodeficiency virus (HIV)
7. Human T-lymphotropic virus (HTLV) I and II
8. syphilis
9. West Nile virus
10. Chagas disease

    The blood cells are irradiated to inactivate any T-lymphocytes present in the donated blood. (T-lymphocytes can cause a reaction when transfused, but repeated exposure to foreign cells can also cause graft-versus-host problems.)

Leukocyte-depleted blood is filtered to remove white blood cells that contain antibodies that can cause fever in the transfusion recipient. (These antibodies, with repeated transfusions, may also increase the recipient's risk of subsequent transfusion reactions.)