A novel fluorescence-based method for protein staining on SDS polyacrylamide gel is described. In this method, proteins are stained using counterion (palmatine and SDS) staining solution, which is inexpensive, easy to perform, and does not involve a destaining step. Fixing and staining of proteins using the counterion protocol take less than an hour. As little as 2 ng of protein can be detected. Another interesting feature of the staining protocol described here is the compatibility with MALDI-TOF MS which shows a similar number of identification score and sequence coverage compared with those of SYPRO Ruby.