We found that fluorescence after CM-FDG staining for B-gal activity
was quite well retained after 3.7% formaldehyde fixation. We presume
that the chloromethyl moiety of CM-FDG reacts with protein thiols. It
should be noted that some of the fluorescent products of CM-FDG, and
also FDG, get lost from cells. With verapamil one can prevent that.
We have submitted a paper describing all this.
Hope this helps,
Martin Poot