[Histonet] Toluidine blue with urea

[Emilien.Gantelet <@t> unil.ch]

Hello histonetters,

I am trying to perform direct counting of motor neurons in mice spinal cord. The fixative does not penetrate correctly in the heart of grey matter, so my usual recipe of 1% Toluidine Blue + 1% borax in distilled water (which is soooo reliable in other cases) just appears to be inefficient : there is strong persistance of a pale haloin the center of my sections (embedded in epoxy).

That's why I'm interested today in adding urea to this recipe. I started with 1% urea. I got perfect results on 2 microns thick sections, but the contrast is far too weak on 1 micron thick sections.
Do you think of anything I could try, to increase this contrast? Or is the 1 micron thickness totally unsufficient to show correctly Nissl with toluidine blue?

Thank you all for your suggestions!

Merry Christmas and happy new 2006 year!!!!

Emilien Gantelet

---------------------------------------------------------------------
Emilien Gantelet, assistant-doctorant
Département de Biologie Cellulaire et de Morphologie (DBCM)
Université de Lausanne
Rue du Bugnon, 9
1005 Lausanne
Switzerland