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HelpTest Code THCX Delta-8 and Delta-9-Carboxy-Tetrahydrocannabinol (THC) Confirmation, Chain of Custody, Random, Urine
Useful For
Detection and confirmation of drug use of cannabis/marijuana and to specifically identify and quantify delta-8 carboxy tetrahydrocannabinol (THC-COOH) and delta-9-THC-COOH
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 always under the control of personnel involved with testing the specimen; this control implies that the opportunity for specimen tampering would be limited.
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| COCH | Chain of Custody Processing | No | Yes |
| ADLTX | Adulterants Survey, CoC, U | Yes | Yes |
Testing Algorithm
Testing for adulterants will be performed on all chain-of-custody urine samples per regulatory requirements.
Reporting Name
Carboxy-THC Confirmation, CoC, USpecimen Type
UrineOrdering Guidance
This test is for situations that require the chain-of-custody process. For testing not requiring chain of custody, order THCU / Delta-8 and Delta-9-Carboxy-Tetrahydrocannabinol (THC) Confirmation, Random, Urine.
Specimen Required
Supplies: Chain of Custody Kit (T282)
Container/Tube: Chain-of-Custody Kit containing the specimen containers, seals, and required documentation.
Specimen Volume: 5 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.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days | ||
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | OK |
| Gross icterus | Reject |
Clinical Information
There are over 100 different cannabinoids in cannabis/marijuana. The main psychoactive cannabinoid is delta-9- tetrahydrocannabinol (delta-9-THC), which is the active agent of the popularly abused street drug, cannabis/marijuana. Delta-8 tetrahydrocannabinol (delta-8-THC) is another psychoactive substance found in the Cannabis sativa plant, of which cannabis/marijuana and hemp are 2 varieties. Delta-8 THC is one of over 100 cannabinoids produced naturally by the cannabis plant but is not typically found in significant amounts in the plant itself. As a result, concentrated amounts of delta-8 THC are typically manufactured from hemp-derived cannabidiol.
Following consumption of cannabis/marijuana, delta-9-THC metabolizes to a variety of inactive products, one of them being the carboxy metabolite (delta-9-THC-COOH). In almost all medico-legal cases or when the patient adamantly denies cannabis/marijuana use and the immunoassay test is positive, confirmation of the result by a definitive test is required. This test is a definitive, confirmatory test using liquid chromatography tandem mass spectrometry to identify and quantify delta-8-THC-COOH and delta-9-THC-COOH.
Chain of custody is a record of the disposition of a specimen to document the personnel who collected, handled, and 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.
Reference Values
Not detected
Positive results are reported with a quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) result.
Cutoff concentrations:
IMMUNOASSAY SCREEN:
<50 ng/mL
DELTA-8 CARBOXY-TETRAHYDROCANNABINOL (THC) by LC-MS/MS: < 5.0 ng/mL
DELTA-9 CARBOXY-TETRAHYDROCANNABINOL (THC) by LC-MS/MS: < 5.0 ng/mL
Interpretation
The presence of delta-8 and/or delta-9 carboxy tetrahydrocannabinol (THC-COOH) in urine is a strong indicator that the patient has used cannabis/marijuana.
THC-COOH has a long half-life and can be detected in urine for more than 7 days after a single 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.
Cautions
No significant cautionary statements
Day(s) Performed
Monday through Sunday
Report Available
3 to 5 daysSpecimen Retention Time
2 weeksPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80349
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| THCX | Carboxy-THC Confirmation, CoC, U | 102114-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 2449 | Carboxy-THC Immunoassay Screen | 19415-9 |
| 618771 | Delta-8 Carboxy-Tetrahydrocannabinol by LC-MS/MS | 20521-1 |
| 36238 | Delta-9 Carboxy-Tetrahydrocannabinol by LC-MS/MS | 20521-1 |
| 36239 | Carboxy-THC Interpretation | 69050-3 |
| 36240 | Chain of Custody | 77202-0 |
Method Name
Immunoassay/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
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.
Method Description
This test includes immunoassay and confirmation with quantification by liquid chromatography tandem mass spectrometry (LC-MS/MS).
The THC immunoassay is based on the kinetic interaction of microparticles in a solutio as measured by changes in light transmission. In the absence of sample drug, soluble drug conjugates bind to antibody-bound microparticles, causing the formation of particle aggregates. As the aggregation reaction proceeds in the absence of sample drug, the absorbance increases. When a urine sample contains the drug in question, this drug competes with the drug derivative conjugate for microparticle-bound antibody. Antibody bound to sample drug is no longer available to promote particle aggregation, and subsequent particle lattice formation is inhibited. The presence of sample drug diminishes the increasing absorbance in proportion to the concentration of drug in the sample. Sample drug content is determined relative to the value obtained for a known cutoff concentration of drug.(Package insert: THC2. Roche Diagnostics; 03/2022)
Carboxy tetrahydrocannabinol (THC-COOH) is extracted from urine by making the urine alkaline to hydrolyze THC-COOH glucuronide. The hydrolyzed samples are diluted for analysis by LC-MS/MS using selected ion monitoring.(Unpublished Mayo method)