ARUP's Laboratory Test Directory

Methotrexate, Sensitive : 2005405

Mnemonic: METREXSN

Methodology: Quantitative 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 separator tubes. Specimens not protected from light.

Stability (collection to initiation of testing): After separation from cells: Ambient: 4 hours; Refrigerated: 24 hours; Frozen: 6 months

Reference Interval:
Effective August 15, 2011
 
Therapeutic Range
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