Re: toluidine blue/Na borate

From:Elizabeth Chlipala

on 9/19/02 2:17 PM, Smith, Allen at wrote:

> The sodium borate opens the resin for a few nanometers so that more
> toluidine blue solution can penetrate the section.  The greater availability
> of toluidine blue makes metachromasia possible.  Toluidine blue stains
> metachromatically when the tissue contains closely-spaced repeating units of
> acid.  The closely spaced acid residues hold the toluidine blue molecules in
> a stack that absorbs a lot of blue light, allowing enough red to pass
> through that the net effect is purple.  [The reason for the stack absorbing
> blue light is not well understood.  The best guess is that blue and only
> blue light has enough energy to kick electrons across the narrow gap between
> the toluidine blue molecules in the stack.]
> Allen A. Smith, Ph.D.
> Barry University
> School of Graduate Medical Sciences
> Podiatric Medicine and Surgery
> Miami Shores, Florida  33161-6695
> -----Original Message-----
> From: []
> Sent: Thursday, September 19, 2002 2:26 PM
> To:
> Subject: toluidine blue/Na borate
> Hey histonetters!!
> I have a question or two.  What is the difference between 1%toluidine blue
> used 
> alone and 1% toluidine blue added to 1% Na borate.  I know that toluidine
> blue 
> is used on paraffin sections for mast cells.  I looked in histonet archives,
> but did not find an answer to my question.  Does anyone know why na borate
> is 
> added? I know that 1% toluidine blue alone is dark blue with light blue;
> add 
> na borate and you get purple and blue.
> Any help appreciated!!
> Dina
Does anyone have the procedure for the Toluidine Blue stain with sodium
borate.  We routinely use this stain for articular cartilage, our current
protocol uses a sodium acetate/ acetic acid buffer, but I'm always willing
to try something different.

Liz Chlipala
BolderPATH, Inc.

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