One Step Strip Style HBsAg Test is a rapid direct binding test for the visual detection of hepatitis B surface antigen (HBsAg) in serum as an aid in the diagnosis of hepatitis B infection. One Step HBsAg Test is based on the principle of sandwich immunoassay for determination of HBsAg in serum. Monoclonal and polyclonal antibodies are employed to identify HBsAg specifically. This one step test is very sensitive and only takes about 25 minutes. Test results are read visually without any instrument.