[Histonet] aldehyde fuchsin prep and double stains for specials

[John A. Kiernan]

The basic fuchsine must be pararosaniline (CI
42500, Basic red 9). Other components of basic
fuchsine (rosaniline, new fuchsine etc) won't
work. You can get pararosaniline as a certified
dye. 

The paraldehyde has to depolymerize. Hydrochloric
acid is for the acid-catalyzed hydrolysis of
paraldehyde, to generate acetaldehyde. Possibly
old HCl might have lost some potency. It is, after
all, a dissolved gas. The active substance
released is acetaldehyde, which some people use
directly. According to Peggy Wenk [J.
Histotechnol. 19(4): 353, 1996] 2.5 ml of
acetaldehyde can be substituted for 1.5 ml of
paraldehyde).
-- 
-------------------------------
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
   kiernan[AT]uwo.ca
   http://publish.uwo.ca/~jkiernan/
   http://instruct.uwo.ca/anatomy/530/index.htm
_______________________________
"Madary, Joseph" wrote:
> 
> Hello my heroes of the histonet, I am having trouble with the aldehyde fuchsin stain.  Not the procedure, the reagent. I have made this stuff up more times than a headhunter whining.  Twice I made it up, changed everything but the basic fuchsin each time.  It will not ripen to that deep purple color, and will not work in procedure either.  I checked the archives and see that one of the many masters of the microtome John Kiernan recommends heating during the prep, I will try that.  The paraldehyde was fresh both times, but was in the fridge at 4 degrees and froze because its melting point is like 11 degree or something.  I called Sigma and they said it changes states all of the time in shipping and at the warehouse and freeze thaw on that stuff is insignificant.  I never had a problem with that before anyway.  Anyway, I need to do a Mast Cell stain and although the investigator is accepting TOL BLU she wants some different procedures, so I will do Torens, as well.  But here is the
> other thing she wants a doubel stain for muci and mast cells, any ideas?  I have tried some but will not share I want fresh thoughts.
> 
> Nick Madary HT/HTL(ASCP)QIHC
> Histology Mgr, Medimmune Inc
> One Medimmune Way
> Gaithersburg, MD 20878
> 
> 3013984745/6113 fax 9745
> 
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