Update Type: Reference range changed
Test Updated: 03/02/2022
Test Overview
Test Methodology

Hexokinase, NADH Endpoint

Test Usage

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

Reference Range *

<1 year: 60 - 150 mg/dL, 1-150 years: 70 - 180 mg/dL.

* 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
  • GLUC
  • Lactose Tolerance Test
  • RBS (random blood sugar)
Chemical Pathology
STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

Specimen Requirements
Collection Instructions

Collect specimen in an SST tube depending on the measurement requested (random, fasting, 1 hour postprandial or 2 hour postprandial). 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.

Special Handling

If fasting specimen desired, patient should be fasting prior to collection.
Falsely elevated potassium levels or falsely decreased glucose levels may result when the specimen remains uncentrifuged for more than 4 hours after collection. MLabs requests that samples for potassium and/or glucose collected at the client site be centrifuged or delivered uncentrifuged within 3 hours of collection. If unspun specimens sent for potassium or glucose testing are received without a collection date and time noted, MLabs will make every effort to obtain this information from the client. The specimen will not be rejected for being uncentrifuged; however, the following comment will be added to the report: "Specimen was received uncentrifuged more than four hours after draw. This may cause falsely elevated potassium level or falsely decreased glucose level. Please interpret results accordingly."

Fasting Specimen
12 hour fasting specimen is recommended; 8 hour fasting specimen is acceptable.
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
CPT Code
Fee Code