Improved Protein Identification by NanoLC/MS/MS using Chip-Based Columns with Integrated Post-Column Addition of DMSO for Increased Sensitivity

NanoLC/MS/MS is the current method of choice for high sensitivity identification of proteins, e.g. for the discovery of biomarkers in plasma or other biological fluids. The solvent system typically used is determined by the requirements for both the chromatography and the electrospray processes. While it has been demonstrated that solvents like DMSO can increase electrospray ionization efficiency and improve sensitivity, the potential adverse effect on chromatographic separation has prevented researchers from adding these to the mobile phases. Postcolumn addition of these solvents is a good alternative, but not easy to achieve in nanoLC because of the unavoidable introduction of dispersion using a post-column Tee and additional connections. This poster introduces an extension to a chip-based nanoLC separation device that includes a Tee that is directly integrated into the chip post-column.