On Fri, 28 Apr 2000, L. Gibbs wrote:

> Sorry, I am not familiar with using Cresyl Violet for feulgen
> staining. I use the above Cresyl for Nissl staining.

  I'm pretty sure that Nissl staining is the only job that
  cresyl violet is used for. It's a cationic (basic) dye, and
  it stains both nucleic acids; also sulphated compounds like
  those in cartilage and mast cells, if present in the section.
  It is one of the dyes certified by the Biological Stain
  Commission, and is sold by larger American vendors (and smaller
  ones too, I'm sure) under the name of cresyl violet acetate.
  It does not have a C.I. number (never having been a commercial
  colorant - the neurobiological market alone just isn't big enough
  to be noticed by the Society of Dyers and Colorists).

  The Feulgen method is quite different: acid hydrolysis removes
  RNA and degrades DNA to a polyaldehyde that is then stained with
  Schiff's reagent. There are Schiff-like reagents that can be made
  by adding thionyl chloride (source of SO2) to aqueous solutions
  of dyes other than basic fuchsine. Possibly cresyl violet is
  one such dye, but this would be a very unusual, obscure technique.
  The only pseudo-Schiff reagent that's seen much use is the one
  derived from thionine, which is used in some of the fancy PAS-type
  methods for sialoglycoproteins. Fluorescent pseudo-Schiff reagents
  can also be made. The one from acriflavine and SO2 is quite
  dazzling in PAS-type staining. The pink to red product seen in
  sections stained by the regular PAS or Feulgen mathod (using
  ordinary Schiff from basic fuchsine) also fluoresces in a quite
  pleasing but not brilliant orange-brown - a fact rarely remarked
  on in modern books and papers.

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