Clinics and Departments

Laboratory Services

Lab Dept:


Test Name:


General Information

Lab Order Codes:




CPT Codes:

82140 – Ammonia

Test Includes:

Ammonia concentration reported in umol/L


Test Indications:

Hyperammonemia may result from several causes, both inherited and acquired. The inherited deficiencies of urea cycle enzymes are the major cause of hyperammonemia in infants. The acquired causes include advanced liver disease. Renal failure and Reye’s Syndrome.

Lab Testing Sections:


Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

1 hour

Special Instructions:

Specimen should be transported to the lab on wet ice within 5 minutes of collection.


Specimen Type:



Green top (Li Heparin) tube

Draw Volume:

0.6 mL blood

Processed Volume:

0.2 mL plasma


Venipuncture only, atraumatic draw. The collection tube should be completely filled, tightly capped, gently inverted to mix and placed on wet ice. Specimen should be transported to the lab on wet ice within 5 minutes of collection.

Special Processing:

Lab Staff: The specimen should be centrifuged, plasma aliquot removed to a plastic sample cup and tested within 20 minutes of collection. Specimens that cannot be tested immediately should be frozen.

Patient Preparation:

Patient should avoid smoking for 1 hour prior to sampling.

Sample Rejection:

Clotted specimens; mislabeled specimens; fingerstick specimens; hemolyzed specimens; specimens not received on ice; lipemic samples


Reference Range:


Range (umol/L)

0 – 13 days:

64 – 107

14 days – 1 month:

56 – 92

1 month – 18 years:

21 – 50

>18 years:

11 - 32

Critical Values:

>150 umol/L




Glutamate Dehydrogenase


Siemens Dimension Vista® AMM Flex® reagent cartridge Instructions for Use, Siemens Healthcare Diagnostics, PN 781119.001, Issue Date: 04-08-2013, REV A

Siemens Dimension Vista® Chem 3 Cal Instructions for Use, Siemens Helathcare Diagnostics, June 1, 2014

Burtis, CA and Ashwood, ER (1999) Tietz Textbook of Clinical Chemistry, 3rd Edition, Philadelphia, PA: WB Saunders Co., p 1146-7.

Jacobs & DeMott Laboratory Test Handbook, Lexi-Comp, Inc, Hudson, OH, 5th Edition, 2001

Biorad Liquichek Ethanol/Ammonia Control Product Insert, Bio-Rad Laboratories, Irvine, CA 92618


8/29/2005: TAT previously listed as 4 hours.
9/1/2014: Updated Patient Preparation, Sample Rejection

  Lab Test Directory
    Microbiology/ Virology
    Other Fluids
    Transfusion Services

  Search Lab Test Directory
    List All Documents

  Lab Staff

  E-mail Lab Services