ARUP's Laboratory Test Directory

Methotrexate : 0090311

Mnemonic: METREX

Methodology: Enzyme Immunoassay
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Collect: Plain red. Also acceptable: Green (sodium heparin), lavender (EDTA), pink (K2EDTA), or gray (sodium fluoride/potassium oxalate).

Specimen Preparation: Protect from light during collection, storage, and shipment. Separate serum from cells within 2 hours of collection. Transfer 3 mL serum to an ARUP Amber Transport Tube. (Min: 1 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Serum collected in separator tubes or gels.

Stability (collection to initiation of testing): After separation from cells: Ambient: 4 hours (if protected from light); Refrigerated: 24 hours; Frozen: 6 months
Reference Interval:
Effective August 15, 2011
 
Low dose 0.50-1.00 µmol/L
High dose/24 hours 5.00 µmol/L or less
48 hours 0.50 µmol/L or less
72 hours 0.10 µmol/L or less
This assay cannot be used to measure concentrations less than 0.30 µmol/L

CPT Code(s): 80299
Cross References: Mexate (Methotrexate)
 
 

 

 

 
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