Alyson Tobin wrote:
>> Does anyone know of a good, simple, stain for lipids in plant tissue? Our
> students are looking at seed storage reserves and comparing oily and
> starchy seeds. In the past I have got them to cut seeds in half and add
> Sudan III to stain for lipids. It is very difficult for them to see the
> staining as Sudan is red and a positive test is the formation of a dark red
> stain on the tissue- hard to see against a red background of dye. Any
> suggestions?
>> Alyson Tobin
>> Dr A.K. Tobin
> Plant Science Laboratory
> Sir Harold Mitchell Building
> University of St Andrews
> St Andrews
> KY16 9TH
> UKWe used to do a similar lab in an intro course. We (the lab tech)
sectioned slices of brazil nut (50 um thick)and floated them in water
contained in a petri dish. The sections were stained on a microscope
slide using a saturated solution of SUDAN IV in absolute ethanol
(filtered). Excess stain was rinsed off of the tissue with water and
lighlty blotted with a kimwipe. A wet mount was then made and observed
under a compound scope. As I recall this seemed to yield good results.
Hope this helps,
Bob in Chico
P.S. A simple microtome can be made using a large Bolt and nut. The
specimen is placed in a well created when the nut is screwed almost to
the point of being off of the bolt. This well containing the specimen
is filled with molten wax and allowed to cool. By tightening the nut
onto the bolt the wax/specimen is forced up beyond the end of the nut
slightly and a razor blade can be "sliced" across the top of the nut
yielding an amazingly good section. The wax usually just falls off of
the section so it does not interfere in any staining procedures.
Cheers
