The standard 2 hour glucose tolerance test is useful for screening for type 2 diabetes in non-pregnant patients.
Spin within two (2) hours of sample collection
Lt green plasma separator (PST)
If a grey top tube will not reach the Central Laboratory within 24 hours of collection, it should be spun down, and the plasma transferred to an AHL False Bottom Plasma/Serum Transport Tube labeled as NaFl plasma.
Additional testing cannot be added on to this sample.
Gold serum separator (SST) tube
Grey Sodium flouride (NaFl) or
False bottom plasma/serum transport vial/tube (AHL)
Refrigerated - 7 days
NaFl whole blood:
Refrigerated - 24 hours
Refrigerated - 3 days
Ambient - 8 hours
The 2-hour glucose tolerance protocol for gestational diabetes is not orderable or supported at Allina Health. This is to ensure that all pregnant patients receive the same standard of diagnostic care. The gestational GTT tests available from our laboratory are the Glucose, gestational screen and the Glucose tolerance, 3 hour gestational, recommended by the American College of Obstetrics and Gynecology (ACOG). If a 2-hour gestational GTT is requested, the provider must be contacted to either (1) place a new order for the Glucose gestational screen (1-hour); or, (2) direct the patient to a different laboratory for administration of the 2-hour protocol.