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Degradation of fixed tissue sections - (Mar/11/2014 )

Hello experts!

I collected brain tissue sections from a fixed mouse brain several weeks ago and mounted them on slides, but never used them. I was hoping I could perform a Nissl stain, but usually I only let sections like this dry out overnight (or a few hours on a slide warmer). Are these sections ok to use? Is there something I can do to rescue the issue--like hydrate the sections then let them dry again?

Details, if they matter: Fixed by PFA perfusion, post-fixed in PFA, whole brain mounted in agar and sectioned with vibratome (75u coronal) and the mounted sections were stored at RT, protected in a slide box.

Your thoughts??




I don't see why not. Rehydrate and go. If the tissue looks intact following rehydration you should be alright. I don't know your protocol, but maybe do a more gradual rehydration to avoid tearing of your tissue or your tissue lifting off of your slide.


Thank you!! Fortunately these tissues arent too important, but I'm hoping my fixation was sufficient to keep proteins intact so that the cresyl violet will adhere properly, and that nonspecific staining won't be greatly increased.

Just to clarify, are you talking about "gradual rehydration" by exposing the tissue to decreasing concentrations of EtOH? I was thinking I might just put a small drop of PBS onto each section, but if some sort of serial/gradual rehydration is better then I would love to hear suggestions.

Whatever I do, I'll post the outcome for everyone.


Hi am new to this forum and was wondering if a histologist actually looks at the slides he or she prepared and makes a diagnoses or if it is solely the work of the pathologist?


We have always used decreasing amounts of ethanol. I have never tested it (have only been told by senior members), but adding PBS/Water/etc. directly to dehydrated tissue on a slide will cause it to lift off and potentially break apart. It should be a gradual hydration to minimize damage to the tissue.


Maybe someone can chime in?