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Order Code CH107
Turnaround Time 24-48 hours
Test Includes


Specimen Requirements
Specimen Source
Transport Container
(Specimen Container)

Lavender-top (EDTA) tube

Preferred Specimens
Minimum Volume (uL)
.5 mL
Collection Instructions
(Transport Temperature)
Tube must be filled completely and kept tightly stoppered at all times. Mix well. Specimen must be placed on ice immediately. After collection, immediately centrifuge the lavender-top tube at room temperature, transfer plasma to a transport tube, and freeze. Label this tube ""Frozen Plasma"". Freeze. Ammonia is stable for several days at -20°C. Caution: Blood ammonia increases rapidly at room temperature. Transport Frozen.
Specimen Stability
Temperature Period
Room temperature Unstable
Refrigerated Unstable
Frozen 21 days
Reject Criteria

Received unfrozen:
Whole blood
Received thawed
PPT Potassium EDTA (white-top) tube

Test Details
Clinical Significance

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 Ranges

M:16-60 umol/L