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Ammonia, Plasma

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Updated Test Information:

Test Description
Ammonia, Plasma
Synonym(s)

NH3 (Ammonia), Plasma
Test ID
NH3V
General Information

Useful for:



  • Assisting in the diagnosis of hepatic coma

  • Investigating and monitoring treatment for inborn errors of metabolism

  • Evaluating patients with advanced liver disease
Specimen Type

EDTA Plasma
Specimen Requirements

Lavender
Specimen Collection / Processing Instructions

  • Specimens should be put on ice immediately after collection

  • Centrifuge at refrigerated temperature (4 degrees C)

  • Aliquot plasma into plastic screw-top tube. Keep on ice

  • Freeze plasma within 2 hours of draw.
Minimum Sample Volume

0.50 mL
Additional Processing Details

  • Plasma must be separated from cells and frozen within 2 hours of collection

  • Freeze plasma on dry ice or in a freezer (-60 to -80 degrees C) for long-term storage or shipment.
Stability

  • Frozen (preferred): 7 days

  • Refrigerated: 2 hours
Unacceptable Specimen Conditions

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Limitations

  • Specimens should be put on ice immediately after collection, centrifuged at refrigerated temperature, and plasma kept on ice until analyzed

  • Proper specimen handling is critical; false increases in ammonia may occur if transport and processing instructions are not strictly followed
Methodology

Photometric, Bromophenol Blue (VITROS Dry Slide)
Estimated TAT

1 day
Testing Schedule

Monday-Sunday
Retention

1 day
CPT Code(s)

82140
Reference Range

≤ 30 mcmol/L
Performing Lab

Mayo
LOINC Code(s)

16362-6
Additional Information