Rapid pre-gel visualization of proteins with mass spectrometry compatibility

Despite all of the prophecies of doom, gel electrophoresis is still prevalent in modern proteomic workflows. However, the currently used protein staining methods represent a serious bottleneck for a quick subsequent protein analysis using mass spectrometry. Substituting traditional protein stains by pre-gel derivatization with visible and mass spectrometry compatible reagents eliminates several processing steps and drastically reduces the sample preparation time. A defined chemistry permits seamless integration of such covalent protein staining methods into standardized bioinformatic pipelines. Using Uniblue A we could covalently stain simple to complex protein samples within 1 minute. Protein profiles on the gels were not compromised and MS/MS based sequence coverages higher than 80% could be obtained. In addition, the visual tracking of covalently stained proteins and peptides facilitates method development and validation. Altogether, this new chemo-proteomic approach enables true "at-line" analysis of proteins