On Tue, 18 Feb 1997, Felicity Lawrence wrote:

> Hello,
>
> Does anybody know of a fluorescent dye for demonstrating features of a
> cotton fibre?  I am looking at running a prac subject for biologists whereby
> I get them to stain textile fibres (since these are readily available) with
> fluorescent dye and look to see which structures take up the dye.  Can
> anyone tell me what is a good stain to use for cotton?  Are there any
> pitfalls I should perhaps know about in advance?  I made up a fluorescein
> dye both in water and in ethanol but had minimal luck with these.  The
> literature is quite sparse but I believe the wall of the cotton fibre to be
> made of cellulose.
>
> I no longer subscribe to this discussion group so would ask that replies be
> sent directly to my email address.  If I am overwhelmed by responses, I will
> summarise these and post them to the list later.
>
> Many thanks for any information you can supply.
>
> Felicity Lawrence
>
> Analytical Electron Microscopy Facility
> Queensland University of Technology
> GPO Box 2434, Brisbane 4000
> Australia
>
> Ph : 3864 2557
> Fax: 3864 5100
>
Dear Felicity,
As Pat Van Oostveld expected I was listening (better reading). Indeed we
were also looking for a fluorescent cellulose stain, other than the UV
excitable probe calcofluor white. Congo red just worked out fine, it's
sensitivity can be compared with that of calcofluor. Exactly as the
latter Congo Red also offers the possibility to determine the
predominant orientation of the fibrils in the wall. Although our paper
(J. Microscopy 177, 1-6, 1995) only reports on cells in culture I can
tell you that the trials on other material, eventually whole roots, works
fine as long as there is no cuticle on top of the cellulosic wall. The
probe is however not specific for cellulose;  in our hands it also
perfectly stains chitins in fungal cell walls (we refer to relevant
litterature in the paper).
I suggest you just try it. I'd be interested to know the results of your
experiments. If you do not want to bother all list-recipients further with
details on this topic, use my personal e-mail address.
Best wishes
Jean-Pierre Verbelen
Univ. Antwerp UIA
Dept. Biology
ph: +32 3 820 2277
fax:+32 3 820 2271
e-mail: [log in to unmask]