Glucose, Plasma
Also known as: Blood Sugar, Fasting Blood Sugar, Random Blood Glucose
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, defined by no caloric intake for at least eight hours. The specimen should be labeled as plasma and mixed well. Plasma should be separated within 45 minutes of collection. Gray-top tubes may be submitted without centrifugation.
Limitations
Glucose concentrations can decrease ex vivo due to glycolysis, which varies with factors like glucose concentration, temperature, white blood cell count, and other factors. Glycolysis can be mitigated using inhibitors like sodium fluoride or lithium iodacetate. In whole blood, glucose is stable for up to 72 hours in the presence of fluoride. In separated, nonhemolyzed, sterile serum without fluoride, the glucose concentration remains stable for 14 days at both room temperature and refrigerated conditions. However, leukocytosis may still increase glycolysis despite fluoride presence.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 1558-6
- 1558-6
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
Entire collection
Minimum Volume
0.5 mL
Container
Gray-top (sodium fluoride) tube or green-top (lithium heparin) tube
Collection Instructions
Separate plasma within 45 minutes of collection. Only gray-top tubes may be submitted without centrifugation. Label specimen as plasma. Mix well.
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
Gross hemolysis; improper labeling; samples unspun or improperly spun (excluding oxalate/NaF)
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |