On Mon, 07 Jun 2004 06:21:53 GMT, Nitrobacter <kazzmaster at hotmail.com> wrote:
> Hey everyone. I'm working on a project about lichen symbiosis, and I'm
> trying to prepare slides of the lichen thallus for investigation.
> Unfortunately, I can't get the slices thin enough to view properly. I
> need slices a few cells thick, nearly transparent. I'm using one of
those flimsy steel razor blades, and it seems to be doing alright.
Try a single edged razor blade for hand sectioning. I do my best
unsupported hand sectioning by holding the specimen upright in my
non-dominant hand, between thumb and forefinger, just barely
above the surface of the thumb and forefinger. Wet the specimen
with a drop of water and a bit of wetting agent (a drop of 1:1000
baby shampoo in distilled water works ok), and then hold the razor
blade parallel to the floor, and slice across the specimen toward
yourself. Slice several times, then spread the sections out in
a drop of water, and choose the thinnest. You may need to cut
20 freehand sections to get what you need, but it can be done.
If you decide you want more support for the thallus, sandwich it
between pieces of elder pith, potato or carrot, and hand section.
There should be whole chapters in older books on botanical microtechnique
that may be helpful. Offhand, I'd suggest something like Sass's
Botanical Microtechnique, Peacock's Elementary microtechnique,
Johansen's Plant Microtechnique, etc.
Hand sectioning is almost a lost art, but it only takes a bit of
practice. If your school has a plant anatomist on staff, s/he can
probably show you easily.