What is the principle of the On-Site Oral screening device?
The oral fluids test is based on competitive binding. Drugs that may be present in the oral fluid specimen compete against their respective drug conjugate for biding sites on their antibody. During testing, a portion of the orrla fluid sample migrates across the membrane. If no drug is present above the cut-off, the sample will not saturate the binding sites of its specific antibody. The antibody will then react with drug-protein conjugate and a visible colored line will show up in the test line region. The presence of a drug above the cut-off concentration will saturate all the binding sites of the antibody and a line will not form in the test region. The lateral flow is the migration and competition across the membrane.
