[Histonet] Bubbling effect under brain tissue sections

[Kerry Broom]

I am having problems with our immunohistochemistry on the dako autostainer - please see attached image of a brain section using synaptophysin antibody.  But, I don't think the problem is the immunohistochemistry, I think it is happening before we get to that stage.
We are using 5% APES coated slides and the sections go through a 95deg heat pretreatment at high pH.
We are getting this bubbling effect under the tissue.  It looks to be worse on one side of the brain (the top of the slide)
Does anyone have any idea what might be causing this?  Any suggestions welcome.
http://histosearch.com/imageupload/bubbling-effect-under-brain-tissue-sections/


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