Specimen Requirements

Patient Preparation

1. For 3 days prior to day of testing, the patient should consume unrestricted high carbohydrate diet (150 g/day) and have normal physical activity.

2. Patient should fast 8 hours prior to start of test.

3. Draw a fasting specimen and include collection time on label.

4. Patient is given 75 g glucose in solution (give children 1.75 g glucose per kg of child’s weight), and note time ingested was completed.

5. Instruct patient as follows:

A. No food.

B. No drinks, only sips of water throughout test.

C. No smoking and limited exercise.

D. Inform laboratory or nursing staff when symptoms of nausea, vomiting, dizziness, dyspnea, or fainting occur.

E. Two hours after glucose ingestion, draw second specimen, and include collection time on label.

Specimen Collection

Specimen must arrive within 72 hours of draw.

Submit only 1 of the following specimens:

Plasma

Container/Tube: Green-top (heparin) gel tube or grey-top (potassium oxalate/sodium fluoride) tube

Specimen Volume: 1 mL of heparinized plasma or potassium oxalate/sodium fluoride blood
Transport Temperature: Refrigerate
Collection Instructions: Fasting (8 hour). Centrifuge within 1 hour of draw. For grey-top (potassium oxalate/sodium fluoride tube, do not centrifuge. Forward promptly.

Note: 1. Indicate plasma.
2. Label specimen appropriately (plasma).

Serum
Container/Tube: Gold-top serum gel tube

Specimen Volume: 0.5 mL of serum
Transport Temperature: Refrigerate
Collection Instructions: Fasting (8 hour). Centrifuge within 1 hour of draw. Forward promptly.

Note: 1. Indicate serum.
2. Label specimen appropriately (serum).