Staining of proteins for 2D SDS‐PAGE using Coomassie Blue—speed versus sensitivity?

Several new fast staining protocols for the visualization of proteins separated by SDS-PAGE utilizing Coomassie Blue staining (CBS) have been described in literature. The sensitivity of a newly designed staining protocol is usually estimated using 1D SDS-PAGE of serially diluted protein samples. However, this approach is not predictive and satisfactory for 2D SDS-PAGE capable of resolving hundreds or thousands of different proteins in a single analysis. In this work, a new fast staining protocol recently introduced by Dong et al. (PLoS One 2011, 6, e22394) was compared to colloidal CBS. The number of detectable spots in 2D SDS-PAGE of identical blood plasma samples in repeated runs was chosen as a sensitivity criterion. Further, the influence of gel boiling on the subsequent protein identification by MS was investigated. In spite of its advantages, the staining protocol according to Dong et al. (PLoS One 2011, 6, e22394) seems to be less sensitive than colloidal Coomassie staining when the number of detected spots is the evaluating criterion. No obvious influence of gel boiling on the protein identification was observed.