We were curious as to why virtually all of the laboratory manuals we examined recommended heat fixation rather than methanol fixation when staining bacteria. In order to gain insight into this, we contacted a number of the authors of these
laboratory manuals and asked them why methanol fixation was not included in their laboratory exercises on bacterial cell staining. Some indicated that they were not aware that methanol fixation was an alternative to heat fixation. Others indicated that since methanol is a toxic and flammable chemical, they were concerned for safety reasons, particularly
since Bunsen burners are used when staining bacterial cells. While safety issues are a valid concern, we believe the dangers associated with the use of methanol (and the ethanol decolorizing agent, for that matter) can be minimized by following certain laboratory safety guidelines.