What Tube for a Ammonia?
Varies by lab: many hospitals use a green-top heparin tube; ARUP asks for EDTA. Always on ice.
- Additive
- Lithium heparin (PST also has gel)
- Inversions
- 8–10 times
- Order of draw
- #4 of 6
Lab-to-lab variation: Green lithium heparin or lavender EDTA, by lab.
Collection and handling
- Place the tube on ice immediately.
- Centrifuge within about 15 minutes; ammonia rises quickly in a standing sample.
Exam tip
Ammonia is the classic "transport on ice" test, alongside lactate.
Where it falls in the order of draw
- 1. Blood culture bottles (aerobic + anaerobic) (Culture media)
- 2. Light blue (3.2% sodium citrate)
- 3. Gold / red-gray (SST) or red (Clot activator (SST also has gel))
- 4. Green / light green (PST) (Lithium heparin (PST also has gel))
- 5. Lavender (or pink) (K2EDTA)
- 6. Gray (Sodium fluoride / potassium oxalate)
Full explanation in the order of draw guide.
Tube requirements differ between labs and assays. Always follow your own laboratory's collection manual.
Drill tubes and order of draw until they stick
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