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Test Code CO2 or LAB55 CO2, Serum or Plasma

Specimen Requirements

Container Type:

Optimal: Gold or Mint*

*For STAT requests

Acceptable: Red or Green

Finger Stick or Heel Poke: Heparinized Capillary Gas

Optimal Collection Volume: 

4.5mL; full tube

Minimum Volume:
  • Adults: 1 mL whole blood
  • Neonates: 1 hep cap gas
Collection Instructions:

Gently invert the sample 5-6 times after collection.

Specimen Transport:

Refrigerate

Processing Instructions: 

1. If serum, allow the specimen to clot for 30 minutes.

2. Centrifuge specimen within 2 hours of collection.

3. After centrifugation, specimen tubes without a gel barrier should have the serum or plasma aliquoted to a false bottom container.

4. Keep the serum or plasma refrigerated until testing can be performed.

Specimen Stability

Specimen Type Temperature Time
Serum* Refrigerated 7 days
Room Temperature 40 hours

*Note: Heparinized plasma in gel separator tubes is less stable than serum and is only suitable for add-on testing up to 2 days following sample collection.

Specimen Rejection Criteria

Hemolysis Mild OK; Moderate OK; Gross Reject
Lipemia Mild OK; Moderate OK; Gross Reject
Icterus Mild OK; Moderate OK; Gross Reject
Other Quantity not sufficient

Useful For

This assay is useful in evaluating acid-base imbalance in the respiratory and metabolic systems.

Methodology

Roche Cobas - Enzymatic

Reference Ranges

23-32 mmol/L

Day(s) Performed

24/7

Expected TAT

Same day

Performing Laboratory

Bronson Laboratory, Chemistry - Kalamazoo, Battle Creek, Paw Paw, South Haven

Sample Retention Time

7 days

CPT Code

82374

LOINC Code

48391-7