| Synonyms | 3 Hour GTT |
|---|---|
| Panel/Profile Component | None |
| Patient Preparation | Fasting 8-12 hours night before the test. See Special Instructions. |
| Specimen Type | Serum or plasma |
| Collection Requirements | Blood should be drawn in a green and yellow (lithium heparin) or plain red (serum) or gold (SST) tube. |
| Minimum Volume | 0.5 mL |
| Cause for Rejection | Unlabeled specimen, QNS, specimen drawn in wrong tube, excessive hemolysis, patient non-fasting, specimen drawn at wrong time. |
| Specimen Handling/Stability | Specimen stable for 2 hours at room temperature if unspun (8 hours if spun). Complete clot formation should take place before centrifugation. Serum or plasma should be physically separated from cells as soon as possible with a maximum limit of two hours from the time of collection. Specimens should be free of particulate matter. |
| Specimen Storage Stability | Specimens are stable for 8 hours at room temperature, up to 4 days at 2-8°C or for up to 6 months when frozen at -20°C or colder. |
| Test Availability | Testing must be scheduled through Central Scheduling by calling (765)983-3358. |
| Turnaround Time | Routine: 8 hours |
| Special Instructions | Fasting 8-12 hours night before the test. A fasting glucometer reading is taken. If the glucose level is <65 mg/dL or >140 mg/dL, the tolerance test is not performed and physician notified. Patient is to consume a 75 gram unit of Glucola within 10 minutes. Timing begins when all glucola has been consumed. Specimens are drawn fasting and at ½, 1, 2, and 3 hours post glucola consumption. |