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HelpTest Code NA Sodium, serum
Laboratory Code
LAB122
Specimen Requirements
Submit only one of the following:
Preferred
Specimen Type: Serum
Container/Tube: Gold Top (SSTII)
Volume: 5.0 mL
Minimum Volume: 0.5 mL serum
Collection Instructions: Allow specimen to clot for 30 mins and centrifuge within 2 hrs.
Acceptable
Specimen Type: Plasma
Container/Tube: Green Top (Li Heparin/PST)
Volume: 4.5 mL
Minimum Volume: 0.5 mL plasma
Collection Instructions: Centrifuge within 2 hrs.
Specimen Stability
| Specimen Type | Serum/Plasma |
|---|---|
| Ambient | 2 weeks |
| Refrigerate | 2 weeks |
| Frozen | 1 year |
Methodology
Potentiometry
Days and Times Performed
24 hrs, TAT 1 day
Specimen Condition
| Gross Haemolysis | Alert/Reject |
|---|---|
| Icterus | OK |
| Lipaemia | OK |
| Others | Not applicable |
Reference Interval
| Age | |
|---|---|
| 0 – < 1 wk | 132 – 147 mmol/L |
| 1 wk – 17 yrs | 133 – 144 mmol/L |
| ≥ 18 yrs | 135 – 145 mmol/L |
Critical Value: <120 mmol/L or >160 mmol/L
Testing Laboratory
National University Hospital
Clinical Chemistry, 67724346
Useful For
Assessment of electrolyte balance.
Service Code
31111
LOINC Code Information
2951-2
Update
Last updated 12/03/2025