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HelpOrder Code MTXSG Methotrexate Post Glucarpidase, Serum
Useful For
Monitoring methotrexate concentrations post-glucarpidase therapy
Documenting failure to respond that may be due to noncompliance
Guiding dosage adjustments in patients with kidney failure
Reporting Name
Methotrexate Post Glucarpidase, SSpecimen Type
SerumShipping Instructions
Ship specimen in amber vial to protect from light.
Specimen Required
Supplies: Amber Frosted Tube, 5 mL (T915)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Amber vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into an amber vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | LIGHT PROTECTED |
| Frozen | 14 days | LIGHT PROTECTED | |
| Ambient | 7 days | LIGHT PROTECTED |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
| Exposed to light >24 hours | Reject |
Reference Values
Nontoxic drug concentration after 72 hours: <0.1 mcmol/L
Method Description
The serum sample is diluted in a methanol containing internal standard. The protein precipitate is mixed and centrifuged, and a portion of the supernatant is diluted with mobile phase for detection by tandem mass spectrometry.(Unpublished Mayo method)
Day(s) Performed
Monday through Sunday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80204
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.