Capillary electrophoresis (CE) coupled to mass spectrometry (MS) detection is a powerful tool for bioanalytical analysis. With our integrated microfabricated CE-ESI devices, we are developing separations strategies targeting identification of peptides and proteins for areas such as single cell analysis, metabolomics and structural proteomics. Our group has done significant work in developing surface coatings to reduce analyte adsorption and optimize the electroosmotic flow (EOF). The results of this are high efficiency separations of intact proteins and peptides from biological matrices. Figure 1 shows a separation of standard proteins using a typical CE-ESI device. All five of the protein components are well resolved and the peaks are Gaussian in shape, indicating a highly efficient separation. Additionally, this data shows the partial separation of α and β hemoglobin subunits and β chain variants. The implications of this are that very similar species, such as post translationally modified proteins, can now be separated using this strategy. Currently, the separations group is focused on intact protein and peptide separations from cell lysates and the analysis of biotherapeutic agents, such as glycoproteins.
Figure 1. CE-ESI separation of a 5 protein standard mixture.