Practical applications of integrated microfluidics for peptide quantification

Background: Increased pressure to obtain more, higher sensitivity data from less sample is especially critical for large peptides, whose already optimized LC–MS methods are heavily challenged by traditional ligand-binding assays. Results: Critical bioanalytical assays were adapted to integrated microscale LC to reduce sample volumes while increasing sensitivity. Assays for teriparatide, glucagon and human insulin and five analogs were transferred from 2.1 mm analytical scale LC to a 150 µm scale system. This resulted in a 15–30 fold overall improvement in sensitivity derived from increased signal to noise, three to six fold reduction in injection volumes, and a two to five fold reduction in sample consumption. Conclusion: Integrated microscale LC reduces sample consumption while enabling single picomolar quantification for therapeutic and endogenous peptides.