Geoff,
         Why bleach out the osmium when you have already stained the 
myelin. A straightforward toluidine blue would do the trick. I've been 
using the Ito & Winchester (1963) stain for many years with great success.
         Sodium tetraborate. =  0.8g.
         Distilled water.        =  100ml.
         Toluidine blue.         =  0.8g.
         Pyronine Y.             =  0.2g.
         Dissolve the borax in the distilled water before adding the two dyes.
         Filter.
Stain at room temperature until the desired colour is obtained. Wash in 
running tap water, air dry and mount in immersion oil or favourite mounting 
medium. I find Entallin best, rapid clearing and setting.

Or, if you have a phase microscope p-phenylenediamine will increase the 
contrast of the osmium fixed tissue..


>Date: Thu, 07 Jun 2001 15:27:05 -0400
>From: Geoff McAuliffe <mcauliff@UMDNJ.EDU>
>Subject: Myelin stain for plastic sections?
>To: "Listserver, Histonet" <HistoNet@pathology.swmed.edu>
>
>Dear List:
>
>     Does anyone know of a myelin stain that works on plastic (Spurr,
>Epon substitutes or methacrylates) sections?  Even better (and more
>unlikely) would be a myelin stain that works on glutaraldehyde-osmium
>(after bleaching out the osmium) fixed material
>
>Geoff
>--
>**********************************************
>Geoff McAuliffe, Ph.D.
>Neuroscience and Cell Biology
>Robert Wood Johnson Medical School
>675 Hoes Lane, Piscataway, NJ 08854
>voice: (732)-235-4583; fax: -4029
>mcauliff@umdnj.edu
>**********************************************