THC

Label Mnemonic:	THCR
Epic code:	LAB7388
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Chemistry
6240 RCP
356-3527

Specimen(s):

Urine Screen + Reflexed Confirmation, Random

Collection Medium:

Clear top tube

Alternate Collection Media:

Urine (Random)-BD Vacutainer^®, no additive yellow top

Minimum:

5 mL random urine

Rejection Criteria:

Test cannot be added to a urine sample previously utilized for urinalysis testing (LAB1160, LAB1164, LAB8379).

Testing Schedule:

24 hrs/day, 7 days a week, including holidays.

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

None

Interpretive Data:

Drug of abuse screening tests are to be used for medical purposes only and not for non-medical purposes (e.g., employee, competitive athlete, or forensic testing).

Comments:

Screen includes THC with a cutoff of 50 ng/mL for the main 
metabolite of THC (9-carboxy-THC).

All positive screening tests are automatically reflexed to a mail-out 
confirmation assay that uses liquid chromatography-tandem mass 
spectrometry (LC/MS/MS) to provide definitive identification and 
quantitation of 9-carboxy-THC.

It is highly unlikely that passive (second-hand) inhalation of 
marijuana smoke will result in a positive screening test.  Research 
studies have shown that maximum urinary concentrations of 9-carboxy-
THC levels only reach 15-20 ng/mL following passive inhalation of 
heavy marijuana smoke.

References:
Cone EJ, Johnson RE, Darwin WD, Yousefnejad D, Mell LD, Paul BD, 
Mitchell J.  Passive inhalation of marijuana smoke: urinarlysis and 
room air levels of delta-9-tetrahydrocannabinol.  J Anal Toxicol 
1987;11:89-96.

Hammett-Stabler CA, Pesce AJ, Cannon DJ.  Urine Drug Screening in the 
Medical Setting.  Clinica Chimica Acta 2002;315:125-135.

Test Limitations:

There is the possibility that other substances and/or factors may interfere with the test and cause erroneous results (e.g., technical or procedural errors). Call the lab at 319-356-3527 for additional information.

Methodology:

Assay is based on the kinetic interaction of microparticles in a solution (KIMS) as measured by changes in light transmission.

CPT Code:

80349

See also:
Drugs of Abuse, Urine
Drugs of Abuse, Urine + Confirm
THC, Urine Screen, Random