Blood Type TestNote: Fasting is not required for this test. The Blood Type Test is performed to determine a person's blood type representing markers (called antigens) on the surface of red blood cells. This test will tell indicate if you're A, B, AB or O, and whether that blood type is positive or negative. There are many types of blood, even though they are made of the same elements. There are eight different common blood types. These eight types are determined by