I use a similar Tol. Blue recipe to stain 1 micron epon sections. I 
usually let it age "a few days", usually a week,  before filtering and 
using - I have had consistant results for 17 years. 

Hopefully letting the soln. age a few days will solve your problem.

Jean Mitchell, BS, HT (ASCP)
University of Wisconsin Hospital & Clinics
Department of Neurology, Neuromuscular Laboratory
Madison, WI

> I don't know how many of use cut plastic sections, but I have a
> question regarding a Toluidine Blue stain solution:
> 
> 1% Toluidine Blue O
> 1% Sodium Tetraborate Dodecahydrate
> 30% Ethanol
> in DDI
> 
> I've been using this stain for years on Epon-Araldite sections and
> Durcupan sections with no problems in getting satisfactory staining. 
> When I have 30-50mL remaining, I always make a new batch so it's ready
> the next time I need it , but this time I forgot.  I made a new
> solution and had to use it right away.  I stained my sections as
> usual, but the color of the sections was bright blue instead of the
> more purple-blue we desire.  Thinking that I'd made a mistake in
> preparing the solution, I made another batch and decided to wait
> overnight to try it, but again the sections were bright blue.
> 
> I was never aware of the need to do this, but does this solution need
> to "ripen" for a week or so before using?  I can't think of any other
> reason. The quality of our water hasn't changed, and everything else
> is the same as I've always used.
> 
> Thank you for any help you can give me.
> 
> Jaclynn M. Lett, Research Technician
> Electron Microscopy Core Facility
> Fay and Carl Simons Center for Biology of Hearing and Deafness
> Central Institute for the Deaf
> 4560 Clayton Ave.
> St. Louis, MO 63110
> 
> jlett@cid.wustl.edu
> 314-977-0257