<span>"They are looking for the presence of antibody or complement on the surface of the RBC." </span><span>The Coombs test is used to diagnose immune hemolytic anemias. It detects the presence of antibody or complement on the surface of the red cell. Answer choice A refers to direct antiglobulin test (DAT). Answer choice B refers to blood smear test. Answer choice C refers to iron stores test.</span>