[Histonet] Metachromasia of mast cells in epoxy resin sections

[gillian.2.brown <@t> gsk.com]

Hi Histonetters,

would any one have experience of counting granules in mouse mast cells in 
tissues which have been formaldehyde fixed, decalcified in a formic acid 
based solution, post osmicated and embedded in epoxy resin?  I'm taking 1 
micron sections and looking to assess the 'degranulation' status of each 
mast cell in terms of how many are still dark blue and how many are pink 
ie based on the metachromatic properties of toluidine blue.  I suppose my 
question is will the formic acid have altered the dye binding properties 
so that I'll get erroneous results?  I'm going to experiment with tissue 
that does not normally have this step but any insights now would be most 
welcome.

Many thanks
Gill Brown


GlaxoSmithKline Medicines Research Centre,
STEVENAGE,