I don't know if this is the right place to post my query, so apologies right from the beginning.
I'm using human tissue 7um thick paraffin section, and am trying to stain elastic fibres. I'm following ACCUSTAIN ELASTIC STAIN kit from Sigma.
After hydration and staining with WORKING ELASTIC STAIN solution for 10 minutes, I differentiate sections in Ferric Chloride Working solution. I do get the desire amount of black colour!
The Problem: The moment section dries out (well, not that I'm leaving it overnight to completely dry it out. I meant, when the "liquid" just leaves the surface of the section), there is an instantaneous reaction that turn the entire section pitch black as if the section was massively over-stained. My next after Ferric Chloride was to counter stain with Van Gieson solution.
The thing I've noticed is that AFTER the section has "dried out", if I dip it back Ferric Chloride I get the same "perfectly" stained section. Also, if I continue with counter staining and then dehydrating it, the moment xylene evaporates I see the same instantaneous reaction under the microscope. Yes, whilst xylene is still "on" the section I can see the "perfect" staining of the section. Leave it for a few seconds under the microscope, I can see the black colour appearing all over the section.
Any idea what's going on??? How to rectify it??
I have also noticed that even after dehydration and when the section is completely "black" under the microscope, if I just dip the slide in xylene for a second, all goes back to "normal". And this can happen to-and-fro. So, what I did was that I didn't allow the xylene to evaporate and immediately mount it. It has retained the "right" staining of the section.