HBsAg Test

The HBsAg test strip / dipstick is composed of sample pad, conjugate pad, nitrocellulose membrane and absorbent pad. The conjugate pad contains colloidal gold conjugated with anti HBsAg and Rabbit IgG. The nitro cellulose membrane is immobilized in form of lines with anti HBsAg at test line region ‘T’ and goat anti-rabbit IgG at control line region ‘C’. When a strip / dipstick is dipped in the serum / plasma up to ‘MAX’ or arrow mark, the specimen is absorbed and migrates immuno-chromatographically by capillary action across the nitro cellulose membrane along with complex of colloidal gold conjugate with HBsAg present in the test specimen. Appearance of pink / purple lines at test line region ‘T’ (towards dipping end) and other line at control region ‘C’ (towards holding end), indicates that test specimen has detectable level of HBsAg. The color intensity of pink / purple line at ‘T’ may vary depending on the concentration of HBsAg present in the test specimen. Absence of the pink / purple line at test line region ‘T’, indicates negative results for presence of HBsAg. The test contains an internal control which should exhibit a pink / purple line at the control line region ‘C’ of the nitrocellulose membrane regardless of color development on the test line regions at ‘T’. If control line region ‘C’ does not appear, the result of the test should be considered as invalid and the specimen must be retested using a new strip / dipstick.