Type A standard serum is type A blood serum containing anti-b antibody, which can be used to identify ABO blood type. 1. According to the distribution of agglutinin A and B, blood is divided into four types: A, B, AB and O. The blood that has only agglutinin A on the red blood cells is type A. Only agglutinin A on red blood cells is A-type blood, and there is anti-B agglutinin in its serum; only agglutinin B on red blood cells is B-type blood, and there is anti-A agglutinin in its serum. 2. Generally, people with blood type A can only receive blood type A during clinical transfusion, and if they receive other types of blood, serious hemolytic reactions will occur, causing patients to have fever, cold, back pain, hemoglobinuria and even renal failure. In case of emergency, a small amount of blood type O can be accepted, but only as a last resort. 3. It is unlikely that the serum of a person with blood type A will contain anti-A antibodies. This is because the red blood cells in the blood of a person with blood type A contain the A-antigen. If A-antibodies are present at the same time, the combination of antigen and antibody will cause a series of lesions. If a person has blood type B, he or she will contain anti-A antibodies.