Insulin, Free and Total
Also known as: INS F&T
Use
This test is used to measure both free and total insulin levels in the blood. It can provide detailed information about insulin secretion and is useful for assessing insulin resistance and hyperinsulinemia. It is important to note that this test is not recommended for diagnosing diabetes mellitus, as it primarily aids in evaluating insulin-related conditions rather than glucose metabolism disorders directly associated with diabetes.
Special Instructions
The test requires serum from a serum separator tube, and 2 mL is needed for testing, although a minimum of 1.1 mL is acceptable. The specimen must be frozen and transported accordingly. Separate specimens must be provided if multiple tests are ordered. Certain conditions such as heparinized specimens, sodium fluoride/potassium oxalate plasma, and hemolyzed specimens are unacceptable for testing.
Limitations
The test reacts almost equally with insulin analogs such as insulin aspart, insulin glargine, and insulin lispro, but insulin detemir shows about 50 percent cross-reactivity. It has negligible reactivity (<3 percent) with insulin glulisine. The test's reference intervals are established for fasting specimens, and results must be interpreted accordingly.
New York Approved
Methodology
Immunoassay (CLIA)
Biomarkers
LOINC Codes
- 6901-3
- 20448-7
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
1.1 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Transfer serum to an ARUP Standard Transport Tube after collection in a serum separator tube.
Storage Instructions
Frozen. Separate specimens must be submitted when multiple tests are ordered.
Causes for Rejection
Heparinized specimens, sodium fluoride/potassium oxalate plasma, and hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 8 hours |
| Refrigerated | 1 week |
| Frozen | 1 month |