This screening test is used to detects Hepatitis B surface antigen (HBsAg). HBsAg is a

protein antigen produced by Hepatitis B virus (HBV). This antigen is the earliest indicator of

acute hepatitis B and frequently identifies infected people before symptoms appear.HBsAg

(hepatitis B surface antigen): when this is “positive” or “reactive,” it means the person is

currently infected with hepatitis B and is able to pass the infection on to others