Detection and confirmation of drug abuse involving delta-9-tetrahydrocannabinol (marijuana) in urine specimens handled through the chain-of-custody process
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
COCH | Chain of Custody Processing | No | Yes |
ADLTX | Adulterants Survey, CoC, U | Yes | Yes |
Testing for adulterants will be performed on all chain of custody urine samples per regulatory requirements.
Immunoassay/Gas Chromatography-Mass Spectrometry (GC-MS) Confirmation with Quantitation
Cannabinoids (Tetrahydrocannabinol)
J (Jane) (Tetrahydrocannabinol)
Jane (Tetrahydrocannabinol)
Marijuana (Tetrahydrocannabinol)
Mary Jane (Tetrahydrocannabinol)
Tetrahydrocannabinol (THC) Confirmation, Quantitative, Urine
TETRAHYDROCANNABINOL, QN
THC (Tetrahydrocannabinol)
Testing for adulterants will be performed on all chain of custody urine samples per regulatory requirements.
Urine
This test is for situations that require the chain-of-custody process. For testing not requiring chain of custody, order THCU / Carboxy-Tetrahydrocannabinol (THC) Confirmation, Random, Urine.
Supplies: Chain of Custody Kit (T282)
Container/Tube: Chain-of-Custody Kit containing the specimen containers, seals, and documentation required.
Specimen Volume: 10 mL
Collection Instructions: Collect specimen in the container provided, seal, and submit with the associated documentation to satisfy the legal requirements for chain-of-custody testing.
1. Chain of Custody Request is included in the Chain-of-Custody Kit (T282).
2. If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.
5 mL
Gross hemolysis | OK |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 14 days | |
Frozen | 14 days | ||
Ambient | 72 hours |
Detection and confirmation of drug abuse involving delta-9-tetrahydrocannabinol (marijuana) in urine specimens handled through the chain-of-custody process
Testing for adulterants will be performed on all chain of custody urine samples per regulatory requirements.
Delta-9-tetrahydrocannabinol is the active agent of the popularly abused street drug, marijuana.
After consumption, either by inhalation or ingestion, the drug is metabolized to a variety of inactive chemicals, one of them being delta-9-tetrahydrocannabinol carboxylic acid.
The immunoassay used to screen for tetrahydrocannabinol (THC) is designed to cross-react with THC carboxylic acid.
In almost all medico-legal cases and in screening of employees, or when the patient adamantly denies THC use and the immunoassay test is positive, confirmation of the result by gas chromatography-mass spectrometry is required.
Chain of custody is required whenever the results of testing could be used in a court of law. Its purpose is to protect the rights of the individual contributing the specimen by demonstrating that it was under the control of personnel involved with testing the specimen at all times; this control implies that the opportunity for specimen tampering would be limited.
This includes a record of the disposition of a specimen to document the personnel who collected it, who handled it, and who performed the analysis. When a specimen is submitted in this manner, analysis will be performed in such a way that it will withstand regular court scrutiny.
Negative
Positives are reported with a quantitative GC-MS result.
Cutoff concentrations:
IMMUNOASSAY SCREEN
<50 ng/mL
THC CARBOXYLIC ACID BY GC-MS
<3 ng/mL
The presence of tetrahydrocannabinol carboxylic acid (THC-COOH), a major metabolite of delta-9-tetrahydrocannabinol (THC), in urine at concentrations greater than 15 ng/mL is a strong indicator that the patient has used marijuana.
THC-COOH has a long half-life and can be detected in urine for more than 7 days after a single use. The presence of THC-COOH in urine greater than 100 ng/mL indicates relatively recent use, probably within the past 7 days. Levels greater than 500 ng/mL suggest chronic and recent use. Chronic use causes accumulation of THC and THC-COOH in adipose tissue such that it is excreted into the urine for as long as 30 to 60 days from the time chronic use is halted.
No significant cautionary statements
1. Moyer TP, Palmen MA, Johnson P, et al: Marijuana testing-how good is it? Mayo Clin Proc 1987;62:413-417
2. Disposition of Toxic Drugs and Chemicals in Man. 10th edition. Edited by RC Baselt. Biomedical Publications, 2014
3. Langman LJ, Bechtel LK, Meier BM, Holstege C: Chapter 41: Clinical Toxicology. In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Edited by N Rifai, AR Horvath, CT Wittwer. Sixth edition. Elsevier, 2018, pp 832-887
Monday through Friday
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
80349
G0480 (if appropriate)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
THCX | Carboxy-THC Confirmation, CoC, U | 20521-1 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
2449 | Carboxy-THC Immunoassay Screen | 19415-9 |
36238 | Carboxy-THC- by GC/MS | 20521-1 |
36239 | Carboxy-THC Interpretation | 69050-3 |
36240 | Chain of Custody | 77202-0 |