Safety Rule: Wear Goggles when working with chemicals
Materials: Two small cups, a Sharpie
pen, tweezers, Onion bulb with roots, razor blade,
toluidine
blue or carbol fuchsin , slide and cover slips, fingernail polish, paper
toweling.
Objective: To prepare a slide of a root to witness mitotic processes.
Procedure:
1. Obtain two small cups. Label
one "HCl" and the other
"Carony".
Pour in enough
of each to cover the bottom of the cups.
2. Use a tweezers to transfer an onion root tip into the cup of HCl.
After 4
minutes, transfer the root into the carony fixative.
The root should remain in the carony fixative for 4
minutes.
After the 4 minutes,
place the root on a slide.
3. Using a razor blade or sharp instrument, cut off 1
to 2 mm of the root tip and discard the rest.
4. Cover the root with a 1 drop of toluidine
blue or carbol fuchsin for 2 minutes.
After the 2 minutes, blot away the stain; be
careful not to touch the root tip.
5. When
the stain has been blotted away, cover the root tips with 1 to 2 drops of
water.
Gently lower a cover slip over
the root tip. Cover the slide with
a paper towel
and with your thumb, firmly press on the cover slip; Do
not twist the cover slip.
The pressure will spread the cells into a single
layer.
6. Then
using the fingernail polish, carefully paint the edges of the cover slip.
Make sure not to move the cover slip.
Finally allow the slide to dry.
Write your name on one side of the slide
and hour of biology.
7. Now
you are ready to view you slide under low power.