Core Laboratory
1. Insulin
Principle:
Electrochemiluminescence Immunoassay "ECLIA". Insulin (in samples) will be incubated with a biothinylated monoclonal specific antibody and a monoclonal insulin-specific antibody labeled with a ruthenium complex, which react to form a sandwich complex. Then the streptavidin-coated microparticles will be added and the complex becomes bound to the solid phase via interaction of biotin and streptavidin. These maicroparticles are going to be magnetically captured onto the surface of the electrode. Application of a voltage to the electrode induces chemiluminescent emission which is measured by a photomultiplier.
Expected values:
The following reference range obtained using ECLIA Test Insulin on samples from 262 healthy, fasting persons, by the original company: 21-118 pmol/L Pathology and Laboratory Medicine, at Mount Sinai Hospital, will validate this normal range (provide own normal range) as soon as possible, but until then, we will refer to mentioned normal range.
Specific performance data of the test:
- Precision:
a. Intra assay is between 1.5 to 2.0 %CV.
b. Total assay precision is between 2.1 to 2.8 %CV. - Analytical sensitivity: The lower detection limit of this test is 1.39 pmol/L.
- Analytical specificity:
| %cross-reactivity | |
| Bovine insulin | 25.0 |
| Porcine insulin | 19.2 |
| Human proinsulin | 0.05 |
| C-Peptide | ND |
| Glucagon | ND |
| Somatostatin | ND |
| IGF-1 | 0.04 |
Limitations - Interface:
- No effect of bilirubin (<90 mg/dl), intralipid (<1800 ng.dk) , biotin (<60 ng/ml) and rheumatoid factors (up to 18,900 U/ml).
- Hemolysis interferes: No effect with the cocktail of inhibitors.
- Anti-insulin antibodies can affect the test.
Measuring (reportable) range:
1.39-6945 pmol/L
For more information, please contact the Core Laboratory manager or director.