You need to determine your blood type through a blood typing lab test. Blood typing test, a determination of the human blood category, is a method of determining the blood type category based on the difference of antigens in the blood. Generally, blood typing labs test for the ABO blood group system and the Rh blood group system. There are four types within the ABO, which are A, B, O, and AB. there are two Rh systems, which are negative and positive. If one is AB rh negative, it is the rarest form of panda blood. Routinely, it is only necessary to draw blood for testing, generally speaking, it is not necessary to fasting, you can eat, you can drink water, in any case, you can draw blood for testing blood type.