[Histonet] Help!! We have a problem with a Mounting Media

[Gayle Callis]

Is anyone experiencing this problem with Protocol Mounting Medium T, 
toluene solvent based from Fisher.

They take 50 mls and put it into a bottle with a secure, air tight, solvent 
resistant lid in order to not dip into stock bottle all the time.
If they use the mounting media absolutely fresh after aliquoting, the 
mounting media drys nicely, everything is fine.  They are coverslipping 
cytospin stained blood cells, Diff Quik stained, and dry without any 
immersion oil used before coverslipping.

If they let the Protocol media aliquot, even though in an air tight, new 
bottle, sit around, they notice a layer or some type of separation within 
top layer of  media.  When they use this now separated aliquot, stirred, 
and then try to dry slide, the coverslip still  slips and slides around - 
failure of drying!!  Very messy!

Something is happening, either evaporation of toluene to change ratio of 
solvent to acrylic resin, maybe something else i.e faulty 
manufacturing/preparation of this media?  This is a total mystery to me as 
I have done this type of aliquoting with other mounting medias for years 
and NEVER had a problem except to add solvent to restore media - thick to 
thinner.   Nor I have never experienced layering/separation phenomena with 
my other mounting media (Richard Allan brand or Permount).   After 
coverslipping, the latter mounting media set up and dry nicely with no 
slip/sliding away!!!



Gayle Callis
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-6367
406 994-4303 (FAX)