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If you have additional questions regarding this test, please call: 415-353-1667
Tetrahydrocannabinol Screen, Urine
|Test Update Information||Effective 01/14/2013, the platform used for the tetrahydrocannabinol immunoassay screen has changed from the Abbot Axsym to the Beckman UniCel DxC 800.|
|Performed by||Parnassus Chemistry|
|In House Availability||Test available 24 hours per day 7 days per week|
|Method||Competitive enzyme immunoassay method (Beckman UniCel DxC800 analyzer) using G6PDH labeling|
|Container type||Urine cup|
|Amount to Collect||See preferred volume|
|Sample type||Random Urine|
|Preferred volume||1 mL urine|
|Min. Volume||0.5 mL urine|
Note: a negative result indicates that this class of drugs is not present, or they are present at a concentration below the cut-off concentration of 50 µg/L
|Synonyms||THC; marijuana; Tetrahydrocannabinol; cannabis; pot; Cannabinoids|
|Stability||Refrigerated 7 days, frozen at -20C 2. weeks|
|Turn around times||Stat 2 hours, Routine 4 hours|
|Additional information||This immunoassay is only a screening test and is not definitive. Results cannot be used for medico-legal purposes.
A concentration of < 50 µg/L is considered negative by this test. A positive result is ≥ 50 µg/L and indicates the presence of this class of drugs.
Cannabis metabolites can be detected in urine up to 95 days after use.( From: Verstraete AG. Detection Times of Drugs of Abuse in Blood, Urine and Oral Fluid. Ther Drug Monit, 26(2) April 2004, 200-205)
False positive results may occur due to other cross reacting substances, however, positive results are NOT routinely confirmed by a second method. If confirmation of the test result is required, it is the responsibility of the physician to separately order a specific confirmatory test for the drug identified. False negative results are also possible, for example, with use of newer JWH compounds and other synthetic cannabinoids.
Click here for List of Cross Reactive Substances
Samples are held for 7 days. Contact laboratory at x 31667 to request confirmatory testing. Confirmation test code THCC.
|Last Updated||1/18/2013 12:05:02 PM|
|Lab Procedure Link||Click here for Procedure|