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HelpTest Code LAB3881 Methotrexate (Post Glucoparidase)
Clinical System Name
Methotrexate (Post Glucoparidase)
Synonyms
MTX
Sample Requirements
Specimen: Whole blood
Container(s):
Preferred: 3 mL blood in GREEN, RED, or LAVENDER TOP tube
Acceptable: 3 mL blood in GOLD SST or LIME PST tube
Preferred Vol: 0.7 mL serum/plasma
Minimum Vol: 0.5 mL serum/plasma
Note: Protect sample from light. In-patients: wrap paper towel around tube and seal with one piece of tape. Off-site: wrap tube in foil. Specimen stable under fluorescent lighting for up to 4 hours.
Processing Instructions
Reject due to: prolonged light/UV exposure, age of specimen
Spin: Y
Aliquot: Y
Storage location: Sendouts Refrigerator (SO UW)
Off-site collection: Specimen should be centrifuged within 2 hours of collection. Spin blood and transfer serum or plasma to plastic tube and protect from light by wrapping tube in foil. Refrigerate.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
|
Serum or Plasma |
RT |
≤ 4 h |
|
Serum or Plasma |
2-8 C |
5 days |
|
Serum or Plasma |
-20 C or -70 C |
|
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | 24/7 | 1 day |
Performing Laboratory
|
University of Washington Special Chemistry Clinical Lab, Room NW220, |
Phone Number: 206-520-4600
Department
Department: Send Outs
Phone Number: (206) 987-2563
CPT Codes
80204
Methodology
Method: Serum/plasma protein precipitation. Analysis by liquid chromatography - tandem mass spectrometry.
Analytical Volume:
Reference Range
The concentration of methotrexate in serum or plasma is determined by liquid chromatography-tandem mass spectrometry after protein precipitation. The reportable range is 0.01 to 2,000 mcmol/L with imprecision between 3 and 14 %CV.
Send Out Instructions
| Reference Test Name: | Methotrexate by LCMSMS |
| Reference Test Number: | MTXG1 |
| Instructions: |
Send out daily with the UW courier. The run is @ 0900 (including weekends) - please send with earliest courier possible. |