Order Code TLUCR Thallium/Creatinine Ratio, Random, Urine
Specimen Required
Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine collection container with no metal cap or glued insert
Submission Container/Tube: Plastic, 10-mL urine tube or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 7 mL
Collection Instructions:
1. Collect a random urine specimen.
2. See Metals Analysis Specimen Collection and Transport for complete instructions.
Useful For
Detecting toxic thallium exposure in random urine specimens
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
TLUC | Thallium/Creat Ratio, U | No | Yes |
CRETR | Creatinine, Random, U | No | Yes |
Special Instructions
Method Name
TLUC: Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
CRETR: Enzymatic Colorimetric Assay
Reporting Name
Thallium/Creat Ratio, Random, USpecimen Type
UrineSpecimen Minimum Volume
2.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Urine | Refrigerated (preferred) | 28 days |
Frozen | 28 days | |
Ambient | 14 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
THALLIUM:
0-17 years: Not established
≥18 years: <2 mcg/g creatinine
CREATININE:
≥18 years old: 16-326 mg/dL
Reference values have not been established for patients who are younger than 18 years of age.
Method Description
The metal of interest is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)
Creatinine:
The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus ver 2. Roche Diagnostics; V15.0, 03/2019)
Day(s) Performed
Tuesday, Friday
Performing Laboratory

CPT Code Information
83018
82570