The test works by detecting both HIV-1/HIV-2 antibodies and HIV-1 p24 antigen in a single sample. When the sample and buffer are added to the sample pad, the mixture migrates to the conjugate pad containing colloidal gold conjugated to HIV antigens. HIV-1/HIV-2 antibodies in the sample bind to these antigens, forming a visible color line in the antibody (Ab) zone. If the sample contains HIV-1 p24 antigen, it will bind to the conjugate and form a visible line in the antigen (Ag) zone.
If HIV antibodies or p24 antigen are absent in the sample, no color line will form in the test zones. A control line (C) confirms the validity of the test.