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Para Aminosalicylic Acid (PAS), Blood (Referred Out) - Saskatoon

Discipline

Microbiology

Overview

Description

Ordering recommendation

Test ordering requirements

Preferred specimen collection

  • Collect peak level 6 hours after dose; to test for delayed drug absorption, a second sample may be collected 4 hours after the peak
  • Specimen should be centrifuged and aliquotted as soon as possible, and frozen within 24 hours after collection

Forms required

  • Fully complete Pharmacokinetics Lab (PK) requisition, including drug dose amount, frequency, method, and date and time of last dose prior to draw located on the National Jewish Health

Clearance required

  • Ordering physician must have test approved by the Microbiologist On Call through RUH switchboard

Alias

  • p-Aminosalicylic acid

Specimen Information

Specimen types accepted

  • Serum

Specimen collection container

  • Preferred collection container: Red (non-gel)
  • Alternative collection container: Dark Green (Li heparin, non-gel; acceptable but not preferred)

Collection procedure

  • Centrifuge and aliquot as soon as possible
  • Freeze within 24 hours

Required volume

  • Optimal volume: One or two full 4.0 mL collection tubes
  • Minimum volume: 2 mL serum
    • (Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection.)
  • Pediatric volume: 0.5 mL serum

Transport and stability

  • Ship frozen on dry ice

Rejection criteria

Testing Information

Clinical interpretation

  • A bacteriostatic agent used against tubercle bacilli

Performance

Days/times performed

Availability
  • Shipped as received, Monday to Thursday
Testing site
  • Referred out by St. Paul’s Hospital Laboratory

 

Maximum laboratory time

Results reporting

  • Within 2–7 days turnaround time by testing laboratory

Last Updated: January 9, 2026