Diabetes GLUCOSE

Clinical Significance
Glucose - Serum glucose levels may be abnormally high (hyperglycemia) or abnormally low (hypoglycemia). Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolic disorders including diabetes mellitus, idiopathic hypoglycemia, and pancreatic islet cell neoplasm.

Preferred Specimen(s)
1 mL serum

Alternative Specimen(s)
Spun SST • Plasma from lithium heparin (green-top) tube in a plastic screw-cap vial • Plasma from sodium heparin (green-top) tube in a plastic screw-cap vial • Plasma from fluoride/oxalate (gray-top) tube in a plastic screw-cap vial

Minimum Volume
0.5 mL

Collection Instructions
Serum and plasma submissions must be separated from cells

Transport Container
Serum Separator Tube (SST®)

Transport Temperature
Room temperature

Specimen Stability
Serum
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days
 
Whole blood (gray-top) tube
Room temperature: 24 hours
Refrigerated: 72 hours
Frozen: Unacceptable
 
Sodium fluoride plasma
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
 
Heparinized plasma
Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 28 days
Reject Criteria
Unspun serum or plasma separator tube (SST® or PST) • Red-top or green-top tube (serum or heparinized plasma not separated from cells) • Anticoagulants other than lithium heparin, sodium heparin or fluoride/oxalate.

Patient Preparation
Fasting preferred. Fasting is defined as no consumption of food or beverage other than water for at least 8 hours before testing.

Methodology
Spectrophotometry (SP)

Reference Range(s)
Fasting Reference Interval    65-99 mg/dL
Non-fasting Reference Interval    65-139 mg/dL