Development of human C-peptide LC-MS isotope-dilution assay : optimization of C-peptide isolation from biological fluids and with ion exchange chromatography

Abstract

Human C-peptide is an effective marker of insulin secretion in diabetes diagnostics, as it is produced in equimolar amounts with insulin. Little metabolism of C-peptide by the liver also enables its concentrations to be three to five times higher than insulin in the plasma. Although there exists a current demand for higher sensitivity, the method of C-peptide quantitative analysis by Isotope-dilution assays allows for greater specificity as compared to current immunoassay methods.