The DRI Cannabinoid Assay is intended for the qualitative and semi-quantitative determination of cannabinoids (THC) in human urine.
The DRI® THC Assay is a homogeneous enzyme immunoassay using ready-to-use liquid reagents. The assay uses specific monoclonal antibody which can detect the major metabolite of Δ9-THC in urine. The assay is based on the competition of a drug labeled with enzyme, glucose-6-phosphate dehydrogenase (G6PDH), and the drug from the urine sample for a fixed amount of specific antibody binding sites. In the absence of drug from the sample, the specific antibody binds the drug labeled with G6PDH and the enzyme activity is inhibited. This phenomenon creates a direct relationship between the drug concentration in urine and the enzyme activity. The G6PDH activity is determined spectrophotometrically at 340 nm by measuring its ability to convert nicotinamide adenine dinucleotide (NAD) to NADH.