The Coombs test is a blood test and is one of the tests used to diagnose anemia. There are two types of Coombs test, his direct test and indirect test. The direct Coombs test or direct antiglobulin test (DAT) is used to detect antibodies that act on the surface of red blood cells. The presence of these types of antibodies indicates a condition known as hemolytic anemia. A direct antiglobulin test is used to detect hemolytic anemia. The indirect Coombs test is only used for pre-transfusion blood tests and prenatal testing in pregnant women.