Specimen Requirements


Lactose Tolerance Test, 5 Specimens (50g)

Specimen Requirement

8 hour fast required.

Immediately after a fasting specimen is obtained, have patient ingest a 50 g dose of lactose. Draw subsequent specimens 1/2, 1, 2 and 3 hours later. Label each with the specific draw time.

Collect 5 SST/ 1.0 mL each, after 30 minutes of clotting, promptly centrifuge, indicate time on tubes and send.


Spectrophotometry (SP)


Room temp: 4 days, Refrigerated: 7 days, Frozen: 28 days

Reference Range

By Report*


1-2 days, Performed Monday-Saturday

Clinical Use

Test includes: Fasting, 30 minute, 1 hour, 2 hour, 3 hour

Results may be used to evaluate deficiency of small bowel mucosal lactase, which may be associated with intolerance to lactose, manifested by diarrhea and other symptoms following ingestion of milk.

Test Code