[Histonet] Histonet: Movat's stain - advice needed!

[Nora Berghoff]

Hello,

I have a question about Russell's modification of Movat's pentachrome
stain.
(Ref.: Russell, HK, "A Modification of Movat's Pentachrome stain", Arch
Path, Vol. 94, Aug 1972, 187-191)

I have been staining canine intestinal sections that have been fixed in
10% neutral buffered formalin, embedded in paraffin and cut at 5um.

The stain worked pretty well and gave good results for a while. Last
week I have had the following problem:

After destaining the crocein scarlet-acid fuchsin with 5%
phosphotungstic acid and then rinsing it in 0.5% acetic acid, it kept
destaining the tissue until everything was just very pale red (one slide
was completely destained - no red stain left whatsoever and the other
stains were pale as well). 
I always control the destaining under the microscope and stop when
there is still intense red color. 
The color kept coming off the slide in the acetic acid solution and
also in the following rinses in absolute alcohol.
I make the solutions (phosphotungstic acid and acetic acid) fresh right
before I need them. 

Does anyone have an idea as to what the problem might be? Is the acetic
acid not strong enough/the phosphotungstic acid too strong, etc?? Is it
a pH problem? 

I have searched for an answer in histo books, on the internet and in
the histonet archives, but couldn't find anything helpful...

Any advice (even if it is just an idea) would be greatly appreciated!!!


Thank you so much,

Nora Berghoff

Research Assistant
Texas A&M University
College Station, TX