Proinsulin ELISA Kit (PI)

INTENDED USE

Human proinsulin ELISA kit is a reliable quantitative procedure for measuring proinsulin (PI, pro-insulin) in human serum and plasma samples. This assay has a minimum sensitivity detection limit of < 0.5 pmol/l.

BACKGROUND

Proinsulin (pro-insulin, PI) is an 86 amino acid which is synthesised by the beta cells of the pancreas. It is also the precursor to the insulin molecule. Only a small portion approx. 15% is released as pro-insulin whereas the rest is converted to c-peptide and insulin, both of these are secreted in equimolar quantity in the blood.

The following assay is intended to measure intact proinsulin and by calculating the molar ration of proinsulin to true insulin (P/I), this can offer a better assessment of ß cell function. The determination of levels in serum can be used to provide vital information in the diagnosis of insulinomas. The levels present in serum is a good reflection of the status of ß cell, levels are found to be elevated in insulin dependent diabetics (IDDM), non-insulin dependent diabetics (NIDDM) and in many other clinical situations. Also, higher levels of circulating are identified in older patients, patients with insulinomas, obese diabetics, pregnant women, functional hyperinsulinemia and hypoglycaemia syndrome.

CONTENT

All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

• Microtiterwells: Break apart strips that are coated with monoclonal anti proinsulin antibody.
• Standards 0-5: Lyophilized human proinsulin, concentrations 0, 2.6, 6.6, 33, 66 pmol/L. The standards are calibrated against the following reference material: WHO 1st International Standard NIBSC code: 09/296.
• Control Low and Control High.
• Sample Diluent.
• Enzyme Conjugate: Consisting of proinsulin antibody conjugated to horseradish peroxidase.
• Conjugate Diluent.
• Assay Buffer.
• TMB Substrate Solution.
• Stop Solution: Contains 0.5 M H2SO4, Avoid contact with the stop solution. It may cause skin irritations and burns.
• Wash Solution (40x Concentrated).

SENSITIVITY

The minimum sensitivity detection limit of human proinsulin (pro-insulin, PI) using current proinsulin ELISA kit was approximately 0.5 pmol/l. The dynamic range for this assay is 2.6 – 66.0 pmol/l.

ASSAY CHARACTERISTICS

– Assay Dynamic Range: 0.5 – 66.0 pmol/L
– Sensitivity: 0.5 pmol/L
– Intra-Assay Variability: 2.9 – 7.4%
– Inter-Assay Variability: 5.5 – 6.8%
– Recovery: 93 – 101%
– Linearity: 100.3 – 106.5%
– Interference: None
– High Dose Hook Effect: No hook effect up to 6000 pmol/L.

REFERENCES

1. Circulating C-Peptide: Measurement and Clinical Applications. Annals of Clinical Biochemistry. (1981) 18: 125. Ashby, J. and Frier, B.
2. Immunoradiometric Assay of Human Intact Proinsulin Applied to Patients with Type 2 Diabetes, Impaired Glucose Tolerance, and Hyperandrogenism. Clinical Chemistry. (1994) 40/5: 754. Chevenne D., et al.
3. Pro-insulin by Immunochemiluminometric Assay for the Diagnosis of Insulinoma. Jorunal of Clinical Endocrinology and Metabolism. (1994) 78:1048. Kao P.C., et al.

ADDITIONAL INFORMATION

• Full Name: Proinsulin ELISA Kit (PI)
• Reactivity: Human
• Sample Type: Serum, Plasma
• Sensitivity: < 0.5 pmol/l

OTHER RELATED ELISA KITS

• Insulin ELISA Kit
• IGF-I ELISA Kit
• C-Peptide ELISA Kit