Specimen Requirements

Patient Preparation:

1. Patient should maintain a normal carbohydrate diet (at least 300 g of carbohydrates per day) for 3 days prior to test. 
2. Patient does not need to fast for this test.
3. Patient must not eat or drink during testing. Ice chips may be given to moisten mouth.

Performance of Test:

1. Have adult patient drink entire 50 g of glucose tolerance beverage.
2. Ingestion should be completed within 5 minutes. Timing starts at this point.
3. Exactly 1 hour after ingestion of glucose beverage, draw blood.

Specimen Collection:

Specimen Type: Plasma or serum
Container/Tube:Light-green top (lithium heparin gel), red top or gold top
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL

Collection Instructions:  Label specimen with time of draw. Complete clot formation should take place before centrifugation.  Spin down and separate cells within half an hour of collection.