>>We want to know which part/cells of tissue takes water up first in a
>>fungal system. I am  wondering if somebody in this group knows some
>>techniques or some dyes (water tracer dye?) that could help us to do
>>this work?
>>I would very much appreciate any response.

>>Haixin Xu  Ph.D.

>This may be totally off the wall, but I recall that water has a very strong
>first order Raman line. Can it be used to image water in this application?

>Aryeh Weiss

Dear Haixin Xu,

Is the fungus dehydrated at the begining of your experiment? If not then
imaging water molecules directly is not likely to help much. In hydrated
tissue, If you looked at the Raman signal you would observe water
everywhere, outside the cells and inside the cells. It is not likely to be
informative. To study water movements in hydrated tissue you would need a
tracer.

If however, you are studying the hydration of dried fungus, then direct
imaging of water might be a possibility. However I would anticipate that at
the wavelengths required for Raman imaging you may see a lot of
autofluorescence from the fungus as well. I'd stick to a simple experiment
using one of the fluorescent tracers others have mentioned already. Many of
the histological dyes fluoresce brightly (that is why they appear so
brightly coloured), and many are so called "vital" (meaning that they can be
used in living organisms). Be wary of photobleaching artifacts though, the
so called vital dyes can cause artifacts when used for fluorescence imaging.

Stephen H. Cody,
Colon Molecular and Cell Biology Laboratory,
Ludwig Institute for Cancer Research,
Post Office Royal Melbourne Hospital,
Parkville, Victoria 3050, Australia.

Tel: 61 3 9341 3155   Fax: 61 3 9341 3104
email: [log in to unmask]
www.ludwig.edu.au/confocal