The nine pre-transfusion tests include Hepatitis B surface antigen, Hepatitis B surface antibody, Hepatitis B core antigen, Hepatitis B core antibody, Hepatitis B e antibody, Hepatitis C virus antibody, syphilis antibody and HIV antibody. The need for blood transfusion is usually associated with severe anemia, massive blood loss due to car accidents, and the need for surgery. The main purpose of conducting the nine tests before blood transfusion is to see if the patient has previously suffered from infectious diseases, so as to avoid medical disputes caused by the discovery of infectious diseases after blood transfusion, and also to avoid serious transfusion reactions. Since the blood group system of the human body is too complicated, so even if the same blood group is transfused, corresponding antibodies may be produced in the recipient’s body and transfusion reactions such as fever and allergy may occur. Therefore, nine tests are required before blood transfusion.