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Cocaine Screen


Immunoassay screen to for qualitative detection of cocaine in urine.

Cocaine (benzoylmethylecgonine) is derived from the plant species Erythroxylon coca, which is widely grown in South America. Cocaine is a very common illicit drug and is popularly abused in the US. Cocaine abuse can produce euphoria, arousal, garrulousness, alertness, anxiety, insomnia, hyperactivity, paranoia, severe psychosis, and even suicide. Cocaine is rapidly metabolized, with less than 5% excreted unchanged in the urine. The two major metabolites, which result from enzymatic and nonenzymatic hydrolysis, are benzoylecgonine and ecgonine methyl ester. The metabolites may be detectable in urine for up to 3 weeks after long term, heavy use of cocaine. 

The cocaine screening assay uses a specific antibody, which can detect benzoylecgonine 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 presence of free drug from the sample, the free drug occupies the antibody binding sites, allowing the drug-labeled G6PDH to interact with the substrate, resulting in enzyme activity. 

In the absence of drug from the sample, the specific antibody binds to the drug labeled with G6PDH and the enzyme activity is inhibited. This phenomenon creates a direct relationship between the drug concentration in the urine and the enzyme activity. The enzyme G6PDH activity is determined spectrophotometrically at 340 nm by measuring the ability to convert nicotinamide adenine dinucleotide (NAD) to NADH.

Test Utility

This test is used to detect the presence of illicit or prescription medications in urine.

Specimen Collection and Preparation

At least 1 mL of urine should be collected in a urine specimen container.

Specimen Storage and Stability

Urine specimen should be stored under refrigerated conditions (2–8°C) until analysis. Samples will also be stored under refrigerated conditions on site for 2 weeks post analysis.

Specimen Rejection

  • Insufficient sample volume

  • Specimen labeled incorrectly or not labeled

  • Specimen validity tests indicate adulterated test

Reference Pages


Monday – Saturday

Result available within 24-48 hours of receipt in laboratory

NOTE: Specimens are refrigerated (2-8°) for 14 days before disposal


Vibra Health Laboratory

1307- A, Allen Dr

Troy, MI 48083

(248) 846-0663

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