Bicarbonate in Human Serum with Roche c502

Detection of Bicarbonate in Human Serum with Roche c502

Test Name: In vitro test for the quantitative determination of bicarbonate in human serum and plasma on Roche/Hitachi cobas c systems.
Method Name: The conversion of bicarbonate to oxaloacetate and phosphate causes the consumption of NADH, and therefore a decrease in absorbance. The concentration of bicarbonate is proportional to the decrease of absorbance in the assay.
Results: Technical Range: 2-50 mmol/L
Reportable Range: 2-38 mmol/L
Reference Ranges: Reference values have not been established for patients <12 months of age. Reference ranges taken from Mayo Clinic Males
12-24 months: 17-25 mmol/L
3 years: 18-26 mmol/L
4-5 years: 19-27 mmol/L
6-7 years: 20-28 mmol/L
8-17 years: 21-29 mmol/L
≥18 years: 22-29 mmol/L

1-3 years: 18-25 mmol/L
4-5 years: 19-26 mmol/L
6-7 years: 20-27 mmol/L
8-9 years: 21-28 mmol/L
≥10 years: 22-29 mmol/L

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination, and other findings.

Clinical Significance: Bicarbonate is the second largest fraction of the anions in plasma. Included in this fraction are the bicarbonate (HCO3) and carbonate (CO32-) ions, as well as the carbamino compounds.

The bicarbonate content of serum or plasma is a significant indicator of electrolyte dispersion and an ion deficit. Together with pH determination, bicarbonate measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with acid‑base imbalance in the respiratory and metabolic systems.

Submission Criteria: For specimen collection and preparation, only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Plasma: Li-heparin plasma

The preferred specimen is from venous blood collected anaerobically in the usual manner for bicarbonate analysis. Bicarbonate content in uncapped tubes decreases approximately 4 mmol/L after one hour. It has been reported that alkalinized serum stored in open cups is stable for up to 4 hours.

The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, therefore not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases.  When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.

Storage and Stability:    7 days at 4-8°C
40 hours at 15-25 °C

Rejection Criteria: Rejection criteria include but are not limited to:
1. Specimens containing fibrin or clots.
2. Excessive platelet clumping
3. Leaking specimens
4. Substandard mixing or collection
5. Expired or improperly stored collection tubes.
6. Improperly filled tubes based on collection tube manufacturer’s guidelines.
7. Contaminated specimens (IV fluid, foreign particles, etc.)
8. Specimens not analyzed within the appropriate time frame.
9. Samples not shipped at appropriate temperature.
10. Samples without 2 proper identifiers or samples having identifiers that do not match the electronic or paper lab requisition.
Authorization: Diagnostic testing can only be performed with approval from an authorized provider/agency.
Turn Around Time: