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Chemistry Specimen Processing

From MedLabWiki

Separate serum/plasma from blood cells within 2 hours

  • For serum, need to wait for specimen to clot first (20-30 min)

Store samples at 4C when not being run

For longer-term storage, store at minimum -20C

Analyte Specimen Type Collection Media Collection Notes Reference Interval
Sodium Lithium heparin 135 - 145 mmol/L
Potassium Lithium heparin 3.5-5.0 mmol/L
Glucose Fasting 4.1 - 5.6 mmol/L
Random
Creatinine Urine, 24 hour
Blood serum Lithium heparin
Urea Blood serum or plasma Lithium heparin 2.1 - 7.1 mmol/L
Urine, random Use thymol preservative and refrigerate
Urine, 24 hour Use thymol preservative and refrigerate 430 - 710 mmol/day
Uric Acid Blood serum or plasma Lithium heparin
Urine, 24 hour
Urinalysis Urine, first morning midstream clean-catch preferred Fresh samples <2h old

Special Samples:

  • Keep on ice
    • Blood gases
    • Ammonia
  • Protect from light
    • Bilirubin
    • Vitamin B12