The five hepatitis B tests, also known as two-and-a-half, are generally divided into the first one for hepatitis B virus surface antigen (HbsAg), the second one for hepatitis B virus surface antibody (HBsAb), the third one for hepatitis B virus e antigen (HBeAg), the fourth one for hepatitis B virus e antibody (HBeAb), and the fifth one for hepatitis B virus core antibody (HBcAb) and hepatitis B virus core IgM antibody ( HBsAb-IgM), which play a very big role in the process of diagnosing hepatitis B and are commonly used in the process of clinical diagnosis. 1, hepatitis B virus surface antigen (HBsAg) HBsAg is the marker of hepatitis B infection in the body, but also in the body’s serum is the first marker of the virus, HbsAg is the shell of the hepatitis B virus, does not contain DNA, so it does not reflect the presence or absence of viral replication, the degree of replication, the degree of infectivity, virus carriers can also be positive HbsAg. 2, Hepatitis B virus surface antibody (HBsAb) is a protective antibody that prevents the hepatitis B virus from entering new liver cells through the cell membrane. a positive HBsAb indicates that the body has a certain degree of immunity to the hepatitis B virus. For hepatitis B vaccine recipients, if only this is positive, it should be considered normal after vaccination. 3. Hepatitis B virus e antigen (HBeAg) indicates that hepatitis B is in the active stage, as a sign of virus replication, and is highly infectious. 4. Hepatitis B virus e antibody (HBeAb) is a sign that virus replication has stopped. 5. Hepatitis B virus core antibody (HBcAb) is a marker that appears in people who have been infected or are infected. The pre-S1 antigen of hepatitis B is another indicator of viral replication, and the earliest immune response to human infection with hepatitis B virus is against the pre-S1 antigen. Since the presence of pre-S1 antigen is at the earliest stage of HBV infection, it can play a role in early diagnosis.