> Date:          Wed, 17 Mar 1999 11:44:00 -0500
> From:          "Yanosy, Bonnie" <lbyano@bpthosp.org>
> Subject:       Elastic stains and Myelin
>
> Hi Histonetters,
> Would any of you know of a  published  reference regarding the staining
> of Myelin by any Elastic tissue staining method. My Pathologist would
> appreciate any info. Thanks, Bonnie Yanosy
>

The following method may be useful:

          WEIL'S MYELIN STAIN

          NOTES:

          Weil's stain is a modification for paraffin sections of the
          Weigert-Pal-Kulschitsky technique for tissue blocks.  The principle of
          these methods involves reduction of chrome salt to chromium dioxide by
          myelin, the chromium subsequently acting as a mordant for the
          Haematoxylin.

          FIXATION:      10% buffered formalin

          MICROTOMY:     8um paraffin sections

          SOLUTIONS:

          1.   Staining Solution:

               a)   Haematoxylin Solution:
                    Haematoxylin stock solution: 10g haematoxylin in 100ml
                         absolute alcohol.  Allow to ripen naturally for 6
                         weeks.
                    Dilute haematoxylin solution 1 part with 4 parts of
                         distilled water for use.

               b)   Iron Alum Solution:
                         4% aqueous ferric ammonium sulphate.

               Mix equal volumes of preheated (56-60 oC) solutions a) and b),
               immediately prior to use.

          2.   2% aqueous ferric ammonium sulphate (differentiating solution).

          3.   Weigert's Differentiator:
                    Borax (sodium tetraborate)         2g
                    Potassium ferricyanide             2.5g
                    Distilled water                    200ml

          CONTROL:       Spinal cord.

          STAINING PROCEDURE:

          1.   Dewax and hydrate sections to distilled water.

          2.   Freshly prepared staining solution at 56-60 oC (slide drying
               oven), 30 minutes.

          3.   Wash well in water.

          4.   Partially differentiate in iron alum differentiating solution,
               until myelin sheaths stand out blueish-black on a pale grey
               background, approx, 5 minutes.  (If unsure, check sections at 
               1 minute intervals).

          5.   Wash in tap water, 10 minutes.

          6.   Complete differentiation in Weigert's differentiator,  1 to 2
               minutes.  Control this differentiation step carefully,
               microscopically, until the myelin is an intense deep blue against
               a creamy background.

          7.   Wash well in tap water.

          8.   Dehydrate, clear and mount.

          RESULTS:

               Myelin                      blue-black
               Red blood cells          black
               Nuclei                        blue
               Background               cream
Tony Henwood
www2.one.net.au/~henwood