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Test Code CO2 Bicarbonate

Additional Codes

Epic Ordering Code LAB55
NBS code LBC01192
Service code 31114

Specimen Requirements

Submit only one of the following:

Preferred: Acceptable:
Yellow Top Light Green Top

Processing Requirements

Allow specimen to clot for 30 mins (Yellow Top) and centrifuge within 2 hours

Specimen type: Serum

Volume: 0.5mL

Specimen Stability

Specimen Type Serum/Plasma
Ambient 1 day
Refrigerate 7 days
Frozen 2 weeks

Send in primary tube, do not aliquot. A consequent decrease in the CO2 value of up to 6 mEq/L

can occur in the course of an hour once the specimen has been exposed to ambient air.

Specimen Condition

Haemolysis OK
Icterus OK
Lipaemia OK
Others Not applicable

Methodology

Enzymatic Assay

Days and Times Performed

24 hrs, TAT 1 day

Reference Interval

Age  (mmo/L)
0 – < 1 wk 15 – 28
1 wk – 1 yr 16 – 29
2 yrs – 9 yrs 17 – 30
10 yrs – 17 yrs 20 – 32
≥ 18 yrs 22 – 32

Testing Laboratory

National University Hospital

Clinical Chemistry, 67724346

Useful For

Evaluation of acid-base status

Update

Last updated 16/07/2026

LOINC Code Information

2028-9

Alias

HCO3

Carbon Dioxide (CO2)