Cacodylic acid sodium salt is used as a buffer (pH buffering range of 5.1 - 7.4), especially for bactericidal buffers used in electron microscopy. The buffering capacity of cacodylate prevents excess acidity that may result from tissue fixation. It is also used in protein crystallisation. Cacodylic acid sodium salt is used as a buffer (pH buffering range of 5.1 - 7.4), especially for bactericidal buffers used in electron microscopy. The buffering capacity of cacodylate prevents excess acidity that may result from tissue fixation. It is also used in protein crystallisation.