Insulin, Serum
Use
This test is useful for diagnosing insulinoma when used in conjunction with proinsulin and C-peptide measurements. It is also employed in the management of diabetes mellitus. Insulin is a hormone produced by the beta cells of the pancreas that regulates glucose uptake and utilization while contributing to protein synthesis and triglyceride storage. Abnormal insulin levels can indicate conditions such as insulinoma or insulin resistance related to diabetes mellitus.
Special Instructions
Patients on insulin therapy may develop anti-insulin antibodies, which can interfere with assay results. For these individuals, measurement of free insulin INSFT / Insulin, Free and Total, Serum should be performed. Specimens need to be labeled carefully with collection times and should be handled to avoid hemolysis as this can impact results.
Limitations
Diagnostic interference can occur due to the presence of antibodies against mouse or other animal antibodies, known as human anti-mouse antibodies (HAMA) or heterophile antibodies, as well as antibodies to streptavidin or ruthenium in rare cases. Hemolysis can interfere with the assay due to the release of insulin-degrading enzymes from erythrocytes. The test has 100% cross-reactivity with recombinant human insulin, but does not recognize other insulin analogues such as insulin lispro, aspart, or glargine.
FDA ApprovedNew York Approved
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 27873-9
- 27873-9
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.75 mL
Container
Plastic vial
Collection Instructions
Avoid hemolysis. Label specimens with collection times. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Patient Preparation
Fasting for 8 hours is required. Avoid biotin supplements for 12 hours prior to collection.
Causes for Rejection
Gross hemolysis and autopsy specimens are rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 180 days |