Specimen Requirements

Patient Preparation

1. Patient should be instructed to eat and drink nothing except water for 10 to 12 hours prior to test.

2. Patient should be instructed to refrain from smoking and drinking coffee just before and during test.

3. Following overnight fast, patient should consume at least a 150 g carbohydrate breakfast.

4. Start timing when patient finishes 150 g carbohydrate breakfast and draw blood specimen after 2 hours.

Specimen Collection

Submit only 1 of the following specimens:

Preferred:

Plasma:

Draw blood in a green-top (lithium heparin) tube from a fasting patient (8 hours preferred). (Hemolyzed or lipemic specimen is not acceptable.) Spin down and send 1 mL of lithium heparin plasma refrigerated.

Note:  

1. Indicate plasma on request form.

2. Label specimen with patient’s name (first and last), date of birth, date and time of draw, phlebotomist’s initials, and as plasma.

Alternate:

Serum

Draw blood in a serum gel tube(s) from a fasting patient (8 hour preferred). (Hemolyzed or lipemic specimen is not acceptable.) Spin down and send 1 mL of serum refrigerated.

Note:  

1. Glucose will drop 5.0 mg/dL to 10 mg/dL per hour in an unseparated, ambient serum gel tube.

2. Indicate serum of request form.

3. Label specimen with patient’s name (first and last), date of birth, date and time of draw, phlebotomist’s initials, and as serum.

Specimen stability:    8 hours at room temperature

                                     3 days refrigerated at  2-8°C
                                   
Minimum volume:      1 mL