A rapid, sensitive and versatile two-site immunoradiometric assay for insulin

Area of Science:

• Endocrinology
• Immunoassay Development
• Biochemistry

Background:

• Accurate insulin measurement is crucial for diagnosing and managing diabetes and other metabolic disorders.
• Existing assays may lack the required speed, sensitivity, or specificity for certain applications.

Purpose of the Study:

• To develop and validate a novel two-site immunoradiometric assay for insulin.
• To assess the assay's sensitivity, specificity, reproducibility, and applicability to biological samples.

Main Methods:

• Utilized a two-site immunoradiometric assay (IRMA) employing a 125I-labelled monoclonal antibody against human proinsulin.
• Employed immunoprecipitation with an immunoadsorbent from polyclonal antisera against bovine insulin for binding assessment.
• Tested reactivity with various insulin types and related peptides, and assessed reproducibility using human insulin standards.

Main Results:

• Achieved a rapid processing time of 60 minutes and a low detection limit of 2 pM.
• Demonstrated similar reactivity for human, rat, bovine, and porcine insulins.
• Showed high reproducibility with coefficients of variation of 2.3% and 5.5% at different concentrations.
• Observed varying but significant reactivity with human insulin-like peptides.

Conclusions:

• The developed IRMA is both rapid and highly sensitive for insulin quantification.
• The assay exhibits broad applicability across different species and sample types.
• This assay is suitable for clinical and research applications, including plasma analysis and in vitro secretion studies.