Specimen Requirements
Title
LACTOSE TOLERANCE TEST, 5 SPECIMENS
Specimen Requirement
Requires five tubes of 1 mL plasma/serum each.
Tube options: Lithium Heparin, Sodium Heparin or SST
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.
Specimen Stability
Sodium fluoride plasma
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Heparinized plasma
Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 28 days
Serum
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days
Whole blood (gray-top) tube
Room temperature: 24 hours
Refrigerated: 72 hours
Frozen: Unacceptable
Methodology
Spectrophotometry (SP)
Stability
See above
Reference Range
By Report*
Turnaround
1 day Performed Mon-Sat
Clinical Use
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
LT5SP