Higher resolution protein band visualisation via improvement of colloidal CBB-G staining by gel fixation

Background Gel staining is a crucial step that allows the visualisation of proteins separated through SDS-PAGE. Colloidal Coomassie Brilliant Blue-G (CBB-G) staining is among the commonly used visualisation methods due to several factors such as compatibility with mass spectrometry (MS) analysis, sensitivity, reproducibility, and simplicity of the staining process. However, the standard colloidal CBB-G staining has a drawback: the resolution of protein bands is compromised because of diffusion of proteins during the washing step. Results A modification to an established colloidal CBB-G staining method, which greatly increases the resolution of protein bands, is described. The addition of a fixation step, which prevents the diffusion of proteins during the washing step, is shown to increase protein band resolution. Conclusion The fixation step is fast, flexible, and also retains all the advantages of the standard colloidal CBB-G staining methods. As there are no drawbacks, incorporating this fixation step into the standard colloidal CBB-G staining is an easy way to improve protein visualisation in SDS-PAGE. Graphical Abstract