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Order Code CH131
Turnaround Time 24 hours
Test Includes


Specimen Requirements
Specimen Source
Transport Container
(Specimen Container)

SST (Tiger Top)
Lithium Heparin/ Sodium Heparin

Preferred Specimens
Minimum Volume (uL)
.5 mL
Collection Instructions
(Transport Temperature)
Keep tube tightly capped for storage. Decreased CO2 can occurin the course of an hour once the specimen has been exposed to ambient air. Transport refrigerated.
Specimen Stability
Temperature Period
Room temperature SST, Lithium Heparin (without gel), Sodium Heparin: 2 hours; Serum Tube, Plasma Separator Tube: 8 hours
Refrigerated Lithium Heparin (without gel): 2 days; Serum Tube, SST, Plasma Separator Tube, Sodium Heparin: 3 days
Frozen 2 weeks
Test Details
PEP Carboxylase
Clinical Significance

The determination of serum carbon dioxide total (CO2) in conjunction with other clinical and laboratory information is necessary for the evaluation of acid-base status. A high CO2 content may be observed in compensated respiratory acidosis and metabolic alkalosis. A low CO2 content may be observed in compensated respiratory alkalosis and metabolic acidosis. Additional laboratory determinations will permit differentiation between metabolic and respiratory conditions.

Reference Ranges

22 – 32 mmol/L

Alternative Names
Carbon Dioxide