Sign in →

Test Code LACTS or LAB2208 Lactose Tolerance Test, Serum or Plasma

Important Note

This is a scheduled test performed at Kalamazoo or Battle Creek. To schedule, please call Bronson Central Scheduling at 269-341-8700 for the Kalamazoo campus or Battle Creek Lab at 269-704-4142 to for the Battle Creek campus. Testing is available Tuesday through Saturday but must be scheduled at least 24 hours in advance.

Please note the patient preparation steps required in the Specimen Requirements section below.

Specimen Requirements

Patient Preparation:
  • Patients should not have anything to eat or drink at least 8 hours before the test. Patients are allowed sips of water.
  • Patients should avoid smoking, chewing gum, or hard candies (such as LifeSavers).
Container Type:

Optimal: Gold or Mint

Acceptable: Red or Green
Optimal Collection Volume: 

4.5mL; full tube
Minimum Volume:

1 mL whole blood
Collection Instructions:
  1. This test includes five separate draws.
    • Fasting
    • 30 minutes 
    • 60 minutes
    • 90 minutes
    • 120 minutes
  2. Draw a fasting specimen.
  3. Administer Lactose.
  4. Draw remaining specimens at the appropriate time intervals.
  5. The patient should remain seated or in bed during the duration of the test.
Specimen Transport:

Refrigerate
Processing Instructions: 
  1. If serum, allow the specimen to clot for 30 minutes.
  2. Centrifuge specimen within 2 hours of collection.
  3. After centrifugation, specimen tubes without a gel barrier should have the serum or plasma aliquoted to a false bottom container.
  4. Keep the serum or plasma refrigerated until testing can be performed.

Specimen Stability

Specimen Type Temperature Time
Serum* Refrigerated 3 days
Room Temperature 8 hours

*Note: Heparinized plasma in gel separator tubes is less stable than serum and is only suitable for add-on testing up to 2 days following sample collection.

Specimen Rejection Criteria

Hemolysis

Mild OK; Moderate OK; Gross Reject

Lipemia

Mild OK; Moderate OK; Gross Reject

Icterus

Mild OK; Moderate OK; Gross Reject

Other

Quantity not sufficient

Patient vomits

Patient not fasting

Useful For

Measuring the body's ability to break down lactose, a type of sugar found in milk and other dairy products.

Methodology

Roche Cobas - Enzymatic with hexokinase

Reference Ranges

NORMAL RESPONSE: An increase in blood glucose of more than 20 mg/dl over fasting level.

ABNORMAL RESPONSE: A flat glucose curve with glucose levels increasing less than 20 mg/dL over fasting levels and symptoms including gas, cramps, and diarrhea is evidence of lactase deficiency.

Day(s) Performed

24/7

Expected TAT

Same day

Performing Laboratory

Bronson Laboratory, Chemistry - Kalamazoo and Battle Creek

Sample Retention Time

7 days

CPT Code

  • Lactose Tolerance - 82951
  • Glucose - 82952