Test Overview
Test Methodology

Hexokinase, NADH Endpoint

Test Usage

Determine glucose level, monitor insulin therapy, evaluate carbohydrate metabolism.

Reference Range *

Fasting <95 mg/dL; 1 hr <180 mg/dL; 2 hr <155 mg/dL; 3 hr <140 mg/dL. A positive diagnosis results from a fasting value equal to or above 95 mg/dL or any two or more values that are equaled or exceeded.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Daily, 24 hours
Analytic Time

2 hours

Soft Order Code
MiChart Code
3HR Glucose Tolerance
  • GLUC3
  • OGTT
  • 3 Hour Gluocose Tolerance
Chemical Pathology
Specimen Requirements
Collection Instructions

Collect blood in an SST tube from a fasting patient. Administer 100 gm Glucola. Instruct patient to finish drinking the Glucola within 5 minutes of the time he or she starts drinking and not to eat anything except a few sips of water after finishing the Glucola. Collect blood in an SST tube exactly 1, 2, and 3 hours after the patient finished drinking the Glucola. Centrifuge within 4 hours of collection, aliquot serum into a plastic vial and refrigerate. If specimen cannot be centrifuged at client site, please arrange for delivery to MLabs within 3 hours of specimen collection. Label vials appropriately (Fasting, 1 HR, 2 HR, and 3HR).

Special Handling

Fasting specimen.

Alternate Specimen
Grey top tube is acceptable if centrifuged and separated within 24 hrs of collection. SST is preferred specimen. [1/98; 4/05; 9/10]
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
Additional Information

Specimen labels are generated at time intervals appropriate for the collection times to be drawn One label to be used for fasting sample at the beginning of testing (GLF) and additional labels to be used on the samples drawn at 1 hour (GL60), 2 hours (GL120), and 3 hours (GL180) after Glucola administration).

CPT Code
Fee Code