ARUP's Laboratory Test Directory

Methotrexate : 0090311

Mnemonic: METREX

Methodology: Fluorescence Polarization Immunoassay   
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Collect:  One 5 mL plain red. Also acceptable: green (sodium heparin), lavender (EDTA), pink (K2EDTA), or gray (sodium fluoride/potassium oxalate).

Transport:  3 mL serum at 2-8°C. (Min: 2 mL)  Submit specimen in an ARUP Amber Transport Tube.

Pediatric Collection/Transport:  1 mL serum or plasma at 2-8°C. 

Remarks:  Do not collect serum in separator tubes or gels.  Separate serum from cells ASAP.  Protect from light during collection, storage, and shipment. 

Stability:  After separation from cells: Ambient: 4 hours if protected from light; Refrigerated: 24 hours; Frozen: 6 months
Reference Interval:
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
CPT Code(s): 80299
 
 

 

 

 
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