[Histonet] aqueous mounting media (gelatin)

[Cheryl]

Hi Jorge-
There are numerous commercially prepared aqueous-based mounting medium.  Most clinical versions are used for immunoflorescent staining.  They're ExPEnSiVe!!   When we use them we dip the slide or add a drop or two of the most recent rinse solution.  For our IF mounts (also temporary) we dip in Ventana's reagent buffer so there is quite a bit of liquid on the slide, then drip a few drops of mounting media right on top of the tissue (centered) and drop the coverslip on flat (not from the edge). 
Press down in the center right over the tissue with a gloved finger. This pressure from a finger drives the more mobile components (bubbles) to the edges away from the tissue we want to see.
It's messy-- you get all sorts of goop out the side of the slides, but these are easily cleaned with a gauze pad soaked in buffer and then left laying flat to dry for a little bit.
Additionally-- thin your gelatin a little so it doesn't get fully firm when cool - with a temp mount the additional liquid won't make any difference except to allow your bubbles to move more freely.  If you need them to last longer without evaporating, you can seal the edges of the slides with fingernail polish or regular mounting media (resinous) left to fully dry. 
Hope this helps! Cheryl Kerry, HT(ASCP) 
Full Staff Inc.