The one step THC (Tetrahydrocannabinol) test is a simple one step immunochromatographic assay for the rapid, qualitative detection of THC and its metabolites 11-nor- 9-tetrahydrocannabinol-9-carboxylic acid in urine.The THC test is based on the principle of the highly specific immunochemical reactions between antigens and antibodies, which are used for the analysis of specific substances in biological fluids. The sensitivity is 50 ng/ml of THC.