This RAPID 1-2-3® HEMA EXPRESS® HEPATITIS B TEST is a lateral flow chromatographic immunoassay. The test device consists of test strip (dipstick) core component enclosed within a protective housing. The test strip is laminated to a sample collection pad. The test strip component of the test devices contains a conjugate pad pre-coated with anti-HBsAg antibody – gold conjugate and a membrane (results window) containing a “Test (T) line” and a “Control (C) line”. The T line is striped with anti-HBsAg antibodies and the C line is striped with anti-IgG antibodies.

When an appropriate amount of specimen is collected on the sample pad of the test device, the sample pad is inserted into the diluent pod and the specimen/diluent mixture migrates by capillary action through the sample pad, into the housing and on to the test strip. The specimen/diluent mixture will first encounter the gold conjugate pad where any HBsAg protein present within the sample will bind to the anti-HBsAg antibody – gold conjugate. The specimen/diluent mixture will migrate further along the test strip next encountering the T line. If HBsAg proteins are present in the specimen at a detectable level, the HBsAg proteins bound to the gold conjugate will bind to the anti-HBsAg antibodies at the T line and will be visibly deposited as a reddish-purple or burgundy line. If no HBsAg proteins are present in the specimen, no binding at the T line will occur and the specimen/diluent mixture will continue migrating along the membrane reaching the C line. The anti-HBsAg antibody – gold conjugate will bind to the anti-IgG antibodies applied at the C line and will be deposited as a reddish-purple line. The presence of both the T and C line indicates a positive result. The presence of only the C line indicates a negative result.