Can we use deionized water instead of mounting medium for confocal microscopy to preventing photobleaching? Since all the parts of the tissue does not mix well with thick mounting medium and therefore micro-air bubble develops.
Mounting media usually contain anti-fading agents, so they help prevent photobleaching. If it is too thick, you could dilute it with some PBS. Of course you could also use plain PBS, if you are in a hurry and you fo not care about keeping the sample in good condition for later. Ideally you should put the medium on the one side, place the coverlip at a 45 degree angle, then slowly lower it so that the medium goes everywhere on the tissue with as few bubbles as possible.