Test Code NH3V Ammonia, Plasma
Specimen Type
Plasma EDTAShipping Instructions
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° C) for long-term storage or shipment.
Specimen Required
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plain, plastic screw-top tube
Specimen Volume: 0.5 mL or more
Collection Instructions:
1. Specimens should be put on ice immediately after collection.
2. Centrifuge at refrigerated temperature (4° C).
3. Aliquot plasma into plastic screw-top tube. Keep on ice.
4. Freeze plasma within 2 hours of collection.
Specimen Minimum Volume
See Specimen Collection
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Plasma EDTA | Frozen (preferred) | 7 days |
Refrigerated | 2 hours |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
Ammonia is a waste product of protein catabolism; it is potentially toxic to the central nervous system. Increased plasma ammonia may be indicative of hepatic encephalopathy, hepatic coma in terminal stages of liver cirrhosis, hepatic failure, acute and subacute liver necrosis, and Reye's syndrome. Hyperammonemia may also be found with increasing dietary protein intake.
The major cause of hyperammonemia in infants includes inherited deficiencies of urea cycle enzymes, inherited metabolic disorders of organic acids and the dibasic amino acids lysine and ornithine, and severe liver disease.
Reference Values
≤30 mcmol/L
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 dayPerforming Laboratory

CPT Code Information
82140
Method Name
Photometric, Bromophenol Blue