[Histonet] Translucent patch

[Adam Boanas]

Hello,

We have recently noticed strange translucent patches that can be seen within our 3 micron tissue sections when they are floated out. From the surface of the water bath they look like holes within the tissue but when the slides are viewed, the tissue is still present. This region of tissue however, creases and folds when mounted. The rest of the section looks and behaves perfectly - it is only this translucent region that is causing the problem. I have seen this region as a small blob but also as a thin streak that runs through the entire section. This region can only be seen for the first 7-10 sections taken. After this the translucent region gets smaller and disappears. This is making getting perfectly flat, artefact free sections of tissue (mouse / rat gut / liver) difficult. Does anyone have any idea what this could be? My thoughts are a possibly processing issue - currently process without vacuum wax infiltration or an embedding issue. Our metal moulds were cleaned with a methanol based para-release spray about 2 months ago by mistake - we have had subsequent tissue spreading issues as a result. Could traces of this affect the cutting surface of the tissue causing this patch?
Any ideas would be great,
Many thanks,
Adam

Adam Boanas
Senior Research Associate
Epistem Ltd
48 Grafton Street
Manchester, M13 9XX