As is the case for DNA and RNA, the protocol for protein extraction is also an adaptation of the protocol used in cyanobacteria. Cells are disrupted using glass beads and vortexing in a 10% glycerol buffer containing the reducing agent DTT to break disulfide bonds within proteins. This extraction will result in denatured proteins, which can be used in SDS-PAGE gels for Western blotting and Coomassie staining.
