On Mon, 24 Jan 2000, Jamie Erickson wrote:

> I am trying to stain mouse eosinophil in formalin fixed paraffin embedded
>tissues. I am using a dye called Vital new red from an Article in the
>Journal of Histotechnology  by J.P.Duffy,  Vol 16/ No. 2/June 1993. The
>article stains human Eosinophil a nice dark red which I'm tring on my
>mouse tissues and getting inconsistent results. After talking to other
>people including ( Gayle Callis)  about differences in human eosinophil
>and mouse eosinophil , I'm thinking that this dye vital new red may have
>to be adjusted to stain mouse eos, that's what I'm doing now. This dye has
>not stained a dark red on positive control tissues it has been a weak pink
>at best. If anyone has experience with this stain or can offer suggestions
>please e-mail me.

  According to Conn's Biological Stains (9th ed, 1977)
  the name vital new red has been applied to at least two
  different disazo dyes, neither of which has been
  manufactured for many years. There is also a disazo
  dye called vital red (CI 23570, Direct red 34), which
  has several synonyms. It was used for blood volume
  determination, along with Evans blue, in the 1920s. The
  Colour Index CD-ROM (1996) says this too has "currently
  no known maker." I've just had a look in 5 catalogues
  and can't find any of these dyes - not surprising if
  nobody makes them.

  The names of dyes mean very little on their own. The
  CI number refers to a specific compound that should
  be the principal ingredient, though in some cases it
  isn't.

  I haven't seen the J Histotechnol paper that you
  mention; it ought to tell you something about the actual
  identity of the dye used (as distinct from its name),
  and where to get it from. If that information isn't
  given, the method can't have much of a future.

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