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HelpTest Code THCCU Delta-9-Carboxy-Tetrahydrocannabinol Confirmation and Creatinine Ratio, Random, Urine
Specimen Required
Only orderable as part of a profile. For more information see THCCR / Delta 9-Carboxy-Tetrahydrocannabinol (THC-COOH) Confirmation and Creatinine Ratio, Random, Urine
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container Tube: Plastic urine container
Submission Container/Tube: Plastic vial
Specimen Volume: 3 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Additional Information:
1. No specimen substitutions.
2. STAT requests are not accepted for this test.
Useful For
Measuring the delta-9 carboxy-tetrahydrocannabinol to creatinine ratio as a part of a profile
Method Name
Only orderable as part of a profile. For more information see THCCR / Delta 9-Carboxy-Tetrahydrocannabinol (THC-COOH) Confirmation and Creatinine Ratio, Random, Urine
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
THC-COOH/Creatinine Ratio, USpecimen Type
UrineSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 14 days |
| Frozen | 14 days | |
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | OK |
| Gross icterus | Reject |
Reference Values
Only orderable as part of a profile. For more information see THCCR / Delta 9-Carboxy-Tetrahydrocannabinol (THC-COOH) Confirmation and Creatinine Ratio, Random, Urine
Not detected (Positive result is reported with a quantitative result)
Cutoff concentration by liquid chromatography tandem mass spectrometry:
Delta-9 Carboxy-Tetrahydrocannabinol: 5.0 ng/mL
Interpretation
Delta-9 carboxy-tetrahydrocannabinol (delta-9-THC-COOH) and creatinine concentrations must be obtained for at least 2 urine specimens with a known time interval (1-7 days) between collections. Using these creatinine-normalized delta-9-THC-COOH concentrations, a ratio is calculated between the concentration of any urine specimen (U2) divided by the concentration in a previously collected urine specimen (U1). The most conservative method for reporting new cannabis/marijuana use between collections would apply a U2/U1 decision ratio equal to the maxima listed in the Table. A more realistic decision ratio with reasonable certainty would be to use the 95% below limits in the same table. U2/U1 ratios above these limits would indicate new usage between those collection time points.
Table. Adapted from Smith ML et al. for less than daily users of cannabis/marijuana.(1)
|
Time interval between urine collections (hours) |
Maximum ratio (U2/U1) |
95% Below (U2/U1) |
|
0-23.9 |
6.29 |
1.42 |
|
24-47.9 |
2.27 |
1.01 |
|
48-71.9 |
1.47 |
0.853 |
|
72-95.9 |
1.63 |
0.595 |
|
96-119.9 |
0.555 |
0.347 |
|
120-143.9 |
0.197 |
0.146 |
|
144-167.9 |
0.080 |
0.073 |
Day(s) Performed
Monday through Sunday
Report Available
3 to 5 daysPerforming 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
G0480
80349 (if appropriate for select payers)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| THCCU | THC-COOH/Creatinine Ratio, U | 19055-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 616334 | Delta-9 Carboxy-Tetrahydrocannabinol by LC-MS/MS | 20521-1 |
| 616335 | Carboxy-THC Interpretation | 69050-3 |
| 616336 | THC-COOH/Creatinine Ratio | 19055-3 |