Specimen Requirements

The patient must be fasting (10-16 hours) and in relatively good health (ie., not nauseous).

Draw lithium heparin whole blood for fasting glucose.

If glucose is >140 mg/dl, consult pathologist. If glucose is <140 mg/dl, give 75 gms (296 ml of S/P Glucose 75 fruit punch) glucose solution. Drink within 5 minutes. No food during test. Water according to thirst. No caffeine or nicotine during test. Vomiting within ½ hour of ingestion of solution voids test.

Collect: 1.0mL of Lithium heparinized plasma or serum at 120 minutes after ingestion of glucose solution.

Serum or plasma must be separated from cells within 2 hours of collection.