visualizing potato plasmolysis

[Jon Monroe]

Hi folks.  In Plant Phys this week the lab is on water relations.  I use the
classic cylinders of potato tissue in a range of sucrose solutions to measure
water potential, but I also have them estimate osmotic potential by observing
incipient plasmolysis in the same solutions.  Half of the groups use potato and
the other half uses beets which, as I understand it, store sucrose instead of
starch, have a much lower osmotic potential, and thus a higher pressure
potential.  With beets it is easy to observe incipient plasmolysis, but they're
having trouble seeing it in the potato tissue.  We tried neutral red but it
seems to stain the cell walls rather than be taken up by the cells.  Does
anyone know how to stain (white) potatoes to see plasmolysis? 

Thanks,  Jon

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  Jonathan Monroe	 	 voice:  540-568-6649 (office)
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