[Histonet] DPX and Entellan mounting medium

[N Fournier]

Hi everyone,

I appreciate the helpful suggestions I received on a previous question. 

I was asked by a colleague to post a question to the group regarding if it was alright to use nail polish in addition to DPX or Entellan Mounting medium to seal slides. They noticed that the slides appeared fine initially (i.e., minimal air bubbles etc) but over a period of time (several weeks) large bubbles formed that surrounded the tissue causing it to dry out. 

Has anyone encountered similar problems. The tissue is 40 to 60 micron thick fixed coronal rat brain sections mounted on gelatin subbed and sometimes Fisher Superfrost Plus Slides. Sections are often stained immunohistochemically using the free-floating method.  I unfortunately do not know the thickness of the coverslip, but I would imagine it is pretty standard guage.  

At first, I thought the problem might be with excess xylene on the slide dissolving the mounting medium or that that not enough was applied. From what I seen I do not believe this is the case but I could be wrong. What they do is run slides through alcohols and xylene. The slides are drained slightly on a Kim Wipe in order to remove some of the residual xylene and then mounting medium and coverslip is quickly applied. Air bubbles are removed by gently pressing them out of the slide. 

Would this method of applying nail polish reduce the occurrence of this problem? Are there any alternative suggestions?

We appreciate your help,

Neil Fournier