Glucose
Also known as: Blood Sugar
Use
Diagnose diabetes mellitus; evaluate disorders of carbohydrate metabolism including alcoholism; evaluate acidosis and ketoacidosis; evaluate dehydration, coma, hypoglycemia of insulinoma and neuroglycopenia
Special Instructions
Blood should be drawn in the morning after an overnight fast, as defined by the ADA as no caloric intake for at least eight hours. Glucose stability is maintained for 14 days at room temperature in separated, nonhemolyzed, sterile serum without fluoride. Use sodium fluoride or lithium iodacetate to inhibit glycolysis if the sample cannot be processed quickly.
Limitations
Glucose concentrations decrease ex vivo due to glycolysis, which can vary based on glucose concentration, temperature, and white blood cell count. Sodium fluoride can maintain glucose stability long-term, but its in-use decrease rate is parallel with other tubes for the first hour post-collection. Leukocytosis can enhance glycolysis even with fluoride present. Glycolysis rates are estimated to decrease glucose by 5-7% per hour.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 2345-7
- 2345-7
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Red-top tube, gel-barrier tube
Collection Instructions
Separate serum or plasma from cells within 45 minutes of collection. Label specimen as serum or lithium heparin plasma.
Patient Preparation
Blood should be drawn in the morning after an overnight fast. Per the American Diabetes Association (ADA), fasting is defined as no caloric intake for at least eight hours.
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Samples unspun or improperly spun (excluding oxalate/NaF); gross hemolysis; gross bacterial contamination; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |