My research interest is to improve the identification performance of capillary zone electrophoresis (CZE) in mass spectrometry based proteomics analysis. Currently, reversed-phase liquid chromatography (RPLC) is the dominant separation method in proteomics analysis. However, CZE outperforms RPLC when dealing with less than tens of nanogram amounts of samples, and it has great potential in ultrasensitive and high throughput proteomics analysis. To overcome the disadvantages of CZE, such as a high concentration detection limit and low sample loading capacity, a solid phase extraction method based on strong cation exchange (SCX) monolith was developed for online sample preconcentration prior to CZE analysis. Moreover, the SCX monolith can be used as a microreactor for online sample preparation to minimize the sample lost and to improve the efficiency.
The developed microreactor-based platform has great potential for single cell proteomics analysis. Currently, a single blastomere of Xenopus embryo is used as a model. A single blastomere has hundreds of nanogram to microgram amounts of proteins depending on embryo stage, and they are significantly different starting from the 8-cell stage. More importantly, the single cell proteomic work on those blastomeres from the same and different stages will be invaluable for understanding blastomere lineage. In terms of sample preparation, we will inject the single cell into the SCX monolith, then do online lysis, reduction and digestion. The sample loss will be decreased to the minimum because the sample was retained on the SCX monolith during all the sample preparation steps. After online digestion, the peptides can be eluted by using single or pH gradient elution for CE-MS or LC-MS analysis.
