The DRI Barbiturate Assay is intended for the qualitative and semi-quantitative determination of barbiturates in human urine.
The DRI® Barbiturate Assay is a homogeneous enzyme immunoassay using ready-to-use liquid reagents. The assay uses monoclonal antibodies that detect most barbiturates in urine. The assay is based on the competition of an enzyme glucose-6-phosphate dehydrogenase (G6PDH) labeled drug 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 G6PDH labeled drug is bound by the specific antibody and the enzyme activity is inhibited. This phenomenon creates a relationship between drug concentration in urine and the enzyme activity. The enzyme G6PDH activity is determined spectrophotometrically at 340 nm by measuring its ability to convert nicotinamide adenine dinucleotide (NAD) to NADH.