Dear Maria,

	No, I was doing confocal microscopy on a 2 congo red controls
earlier this
year, 1 I prepared in 1991(pancreatic section), & the other I added to my
collection in 1996 (renal section).  Both were clearly positive under both
bright & fluorescent light.  Neither have had any special treatment except
for storage in slide boxes when not in use.  Both specimens were prepared
as per standard protocol.

	I seem to remember hearing some years ago that the control tissue
can be
affected by prolonged (months-years) exposure in fixative.

	Regards

	Rob W.

At 05:01 PM 1/27/99 -0500, you wrote:
>Has anybody observed positive Congo red stains fading to weakly positive or
>negative in one month's time?
>
>
>
>
R. Wadley, B.App.Sc, M.L.S
Laboratory Manager
Cellular Analysis Facility
School of Microbiology & Immunology
UNSW 2052
Ph (BH) 	+61 (2) 9385 3517
Ph (AH)	+61 (2) 9555 1239
Fax 	+61 (2) 9385 1591
E-mail	r.wadley@unsw.edu.au
www	http://www.unsw.edu.au/clients/microbiology/CAF.html
	(Under development)