Re: Amido-Schwartz

From:"J. A. Kiernan" <>

On Mon, 13 Nov 2000, Cox, Elizabeth wrote:

> Can anyone tell me what Amido-Schwartz is? A colleague is trying to stain
> fish otoliths but the method does not give much detail on what this stain
> is.

  Sounds like amido black 10B, which has various synonyms
  including naphthol blue black, buffalo black NBR and 
  naphthalene black 10B. The CI number 20470 and application
  name Acid black 1 identify the compound more certainly.
  It's in the Sigma catalogue as naphthol blue black, and
  they sell two grades ($22 or $42 per 100g, with 50% and
  80% dye content respectively). I'm sure other chemical
  companies and stain vendors also have it in their lists.
  It's used by biochemists for staining proteins in 
  electrophoresis gels.

  The usual histological use of this dye is the collagen
  stain in a mixture with picric acid (replacing the
  acid fuchsine in van Gieson's mixture). I don't know
  which grade would be better for this purpose, but
  common sense seems to say that the one with higher
  dye content could always the used at lower concentration
  if necessary. This is a dis-azo dye and almost certainly
  contains more than one coloured product, and possibly
  other impurities that might help or hinder the staining

  I've not used this dye myself. For discussion and
  references see RD Lillie 1977. Conn's Biological
  Stains, 9th ed, pp 142-143. One of Lillie's comments is
  that some brands sold as C.I. Acid black 1 are "excellent"
  whereas others are "quite unsuitable" for staining fine
  collagen & reticular fibres and basement membranes from
  mixtures with picric acid.

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1

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