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Test Code AMMON Ammonia, LAB47


Glutamate Dehydrogenase

Performing Laboratory

St. Luke's Hospital Cedar Rapids

Specimen Requirements


Preferred: Green-top (lithium heparin) tube (PST or No gel)

Acceptable:  Lavender (EDTA) tube
Specimen Volume: 0.25 mL of plasma

Stability: Separated specimens may be stored refrigerated or in ice water for up to 2 hours. 

                Samples should not be frozen.  Specimens should be to the testing lab within 1 hour of collection.

Note:  Venipuncture should occur prior to sulfasalazine and/or sulfapyridine administration due to the potential for falsely depressed results.


Collection Instructions: Forward promptly.

  • The specimen should be drawn from a statis-free vein. 
  • The tube should be completely filled, stored tightly capped on ice, centrifuged immediately, and forwarded to the laboratory promptly.
  • Concentration of ammonia may more than double in plasma if stored at room temperature, so it is important that samples are processed right away. 
  • Samples should not be frozen. 
  • Hemolyzed samples are unacceptable.

Reference Values

0-32 µmol/L

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding


Useful For

Ammonia measurements are used in the diagnosis and treatment of severe liver disorders such as cirrhosis, hepatitis, acute and subacute liver necrosis, and Reye’s syndrome.