Test Code NH3 Ammonia
Laboratory Code
LAB47
Specimen Requirements
Specimen Type: Plasma
Container/Tube: Green Top (Li Heparin)
Volume: 4.5 mL
Minimum Volume: 0.5 mL plasma
Collection Instructions: Place specimen in ice and send to laboratory immediately.
Specimen Stability
| Specimen Type | Plasma |
|---|---|
| Ambient | Reject |
| Refrigerate | 2 hours, separate plasma from cells and refrigerate within 15 minutes of collection/draw time. |
| Frozen | 3 weeks, separate plasma from cells and freeze within 15 minutes of collection/draw time. |
Methodology
Enzymatic Assay
Days and Times Performed
24 hrs, TAT 1 day
Specimen Condition
| Gross Haemolysis | Alert/Reject |
|---|---|
| Icterus | OK |
| Lipaemia | Alert/Reject |
| Others | Not applicable |
Reference Interval
18 – 72 umol/L
Critical value: > 100 umol/L
Testing Laboratory
National University Hospital
Clinical Chemistry, 67724346
Useful For
Assessment of liver function.
Paediatrics: Screening test for amino acid disorders, organic acid disorders and urea cycle disorders.
Service Code
31929
LOINC Code Information
16362-6
Update
Last updated 05/09/2025