Ammonia, Plasma

Abbrev Code:AMMON   
Order Code:LAB47Order Name:Ammonia
Methodology:Roche: Enzymatic with glutamate dehydrogense (GLDH)
Woodwinds: Enzymatic (glutamate dehydrogenase)
CPT Codes: 82140 x1, 82140 x1
Turnaround Time:Performed and reported 24 hours/day.
Special Instructions:Delay in separation introduces more variation than delay in testing once separated. Process sample within 15 minutes of collection. Samples must be placed on wet ice immediately upon collection. Instant cold packs are unacceptable.
Associated Links:

Roche Go Live Schedule

Collection Instructions

Optimal Volume:2.5 mL
Minimum\Peds Volume:0.6 mL
Collection Instructions:
Chemistry Tests Containers Chart
  • Cleanse site thoroughly.
  • If possible, collect directly into vacutainer tube (with gel) without removing stopper; fill tube completely. Capillary draws are unacceptable.
  • Place sample on wet ice immediately upon collection. Instant cold packs are unacceptable.
  • For inpatients: Deliver sample to laboratory within 5 minutes of collection. UMMC West Only: Specimens should be walked directly to laboratory upon completion of collection.
  • For outpatients: Process sample within 15 minutes of collection. See Processing and Shipping Instructions below.
  • For Outreach clients: Deliver sample within 15 minutes of collection to nearest laboratory for processing. If sample cannot be processed within 15 minutes of collection, the patient must be drawn at a facility with a centrifuge.
Causes for Rejection:Hemolyzed, lipemic or grossly icteric specimens or specimens collected by capillary collection.
Whole blood not on placed on wet ice after collection. Whole blood samples not processed within 15 minutes of collection. Plasma samples greater than 2 hours old and/or not placed on wet ice and refrigerated. Frozen plasma more than 6 hours from collection (Non-Roche testing sites only).

Processing and Shipping

Specimen Processing:Within 15 minutes of collection, centrifuge and aliquot 1.25 mL, 0.2 mL minimum, at refrigerated temperature if possible. Place plasma on wet ice and refrigerate up to 2 hours. Alternatively, frozen samples are stable for 3 days at -20 (Roche) or 6 hours at -20 (Non-Roche). Do not freeze the original collection container.
Shipping Instructions:Ship plasma at refrigerated temperature on wet ice to arrive within 2 hours of collection.
Outreach clients: Freeze samples at -20 and ship to arrive within 3 days to a Roche site. For Non-Roche sites, freeze at -20 and ship to arrive within 6 hours of collection. 
Stability:Roche: 30 minutes at room temperature; 2 hours refrigerated; 3 days frozen at -20; 4 weeks frozen at -60.
Test Performed at or Referral Lab Chemistry  (Roche-CSC Mpls, Roche-Grand Itasca, Roche-Lakes, Roche-Northland, Roche-Range, Roche-Ridges, Roche-Southdale, Roche-St. John's, Roche-UMMC East, Roche-UMMC West, Woodwinds)


Critical Range:Greater than 100 umol/L
Reference Range:Roche: Female: 11-51 umol/L;  Male: 10-60 umol/L
Woodwinds: 11-35 umol/L
Use:Evaluation of suspected hepatic disease.

Click HERE to Report test errors or omissions.
*If no email program is associated with this computer, please contact:
[email protected] for TestID: 538"