On Mon, 10 Jan 2000, Nader, Alexander wrote:

> There's a not very well known method published by Csaba 1969 (Acta
> biologicae academicae scientiarum hungaricae, 20, 205) on a double staining
> technique for mast-cells using alcian blue and safranin. It can be found
> also in Bancroft & Stevens book "Theory and Practice of Histological
> Techniques". It is a pretty nice stain, showing mast-cells in two different
> colours (depending on their granula)...

  There is quite a large body of literature dealing with the
  alcian blue-safranine method, especially in connection with
  mucosal vs connective tissue mast cells. I think the first
  use of this technique was by G Jasmin & P. Bois (1961) Rev.
  Canad. Biol. 20: 773-774.  J. Tas (1977) investigated the method
  and showed that different colours imparted by this combination
  of dyes had no histochemical significance (Histochem. J. 15:801-804).
  A more recent paper that does not support the validity of
  alcian blue-safranine for recognizing 2 types of mast cell
  is by KR Tainsh and FL Pearce (1992) Intl Arch. Allergy
  Immunol. 98: 26-34.

  Almost any combination of different methods of carbohydrate
  histochemistry will reveal different "types" of mast cell.
  For example, some dermal mast cells of the rat are PAS-positive
  and also bind concanavalin A, but others are not (Arch.
  Dermatol. Res. 258: 69-80, 1977).

  If you define a mast cell as one with granules that contain
  heparin, they will all stain with alcian blue (or any other
  basic dye) at pH 1, and they will all stain metachromatically
  (red) with blue thiazine dyes such as toluidine blue,
  azure A or thionine. The metachromasia, which is due to
  heparin, was the original defining characteristic of the
  mast cell recognized in 1877 by Paul Ehrlich, about 60 years
  before the discovery of heparin. Mast cells of rodents are
  all stainable, even in paraffin sections, by methods for
  serotonin. I can recommend Lillie's diazosafranine method
  for this purpose, but it's slightly more troublesome to
  do than staining with a basic dye, and it won't work on
  the mast cells of most species other than rat & mouse.

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1
   E-mail: kiernan@uwo.ca