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Barbiturates Screen


Immunoassay screen for qualitative detection of barbiturates in urine.

Drug abusers may abuse various barbiturates, such as short-acting secobarbital and long-acting phenobarbital, through oral ingestion or by intravenous and/or intramuscular injection. Long-term abuse can lead to respiratory depression or, in severe cases, coma. When ingested, a barbiturate is rapidly metabolized and excreted into urine, allowing immunoassays to detect recent use. 

The barbiturate screening 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 the 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.

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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