Sensitive glucagon quantification by immunochemical and LC-MS/MS methods

The peptide hormone glucagon plays an important role in homeostasis of glucose concentrations in the blood. Its biological importance is evidenced through the conservation of its peptide sequence between species. Reliable assays for glucagon in biological samples are important for gaining a better understanding of the pathology and treatment of diabetes. Numerous assays are available for the analysis of glucagon in biological samples, the majority of which employ an immunochemical approach and have been available for many years. However, recent advances in MS instrumentation and the amenability of glucagon for analysis by LC-MS/MS has brought these new methods to the forefront. Concentrations of glucagon determined from different methods are not always consistent and this review provides suggestions of how to improve the reliability of methods for glucagon analysis.