The InnoScreen Quick Cup Urine Drug Testing employs an immunoassay technique based on the competitive binding principle. The test detects drugs in the urine specimen by determining whether they compete with their respective drug conjugate for specific antibody binding sites.
During the test, a portion of the urine sample migrates upward via capillary action, and if a drug is present in the urine sample below its cut-off concentration, it will not saturate the binding site of its specific antibody. In this case, the antibody will react with the drug-protein conjugate, leading to the appearance of a visible coloured line in the corresponding drug strip’s test line region. However, if the drug concentration in the urine sample is above the cut-off concentration, it will saturate all the binding sites of the antibody, and no coloured line will appear in the test line region.
A non-negative urine specimen, in which drug competition occurs, will not generate a coloured line in the test line region of the strip, while a drug-negative urine specimen will generate a line in the test line region due to the absence of drug competition. To ensure the test’s accuracy, a coloured line will always appear in the control line region, indicating that the appropriate volume of specimen has been added, and membrane wicking has occurred.
