Message-Id: <v01510102b1ff5ed37124@[205.134.240.130]>
Date: Tue, 18 Aug 1998 08:51:40 -0800
To: pinhole@exploratorium.edu
From: bcomet@sirius.com (Burt C. Kessler)
Subject: Re: pinhole re: leaves
I don't know how to remove all but the veins, however, I learned a new
trick with leaves this summer. The full lab is an open ended Inquiry
investigation, it can be found at the following URL:
http://www.woodrow.org/teachers/biology/institutes/1998/stomata/
The lab uses superglue to create an impression of the surface of a leaf.
The impression is detailed enough to examine under a microscope and measure
the degree to which the stomata have opened. The leaves can be treated in
various ways to affect the opening or closing of the stomata. The
technique is quick and simple.
I have copyied the basic procedure from the lab below:
1. On a clean glass slide, dispense a small amount of superglue, about one
quarter the size of a pea.
2. Let the drop sit for a few seconds. (if more than 30 seconds, the glue
adheres to the glass in a circle,
and won't imprint)
3. Obtain a large leaf and press the underside into the drop of glue.
4. Apply firm pressure to the leaf for approximately 30 seconds. (The
thinner the leaf, the shorter the
time; pea leaves should be held about 20 seconds, holly leaves about 60
seconds) Students may need
to place a paper towel over the leaf so their fingers don't stick to the slide.
5. Remove pressure, and let the leaf remain on the glue for another 15 -
20 seconds.
6. Carefully peel the leaf off of the glue. (Some of the leaf may stick in
the glue, try to get most off)
7. The imprint will be in the glue; let the glue dry before viewing.
Burt C. Kessler
The best way to get something done is to begin.