16
For transparent objections (e.g. protozoa), on
the other hand, the light shines from below,
through the opening in the microscope stage
and then through the object.
The light travels further through the objective
and eyepiece, where it is also magnified, and fi
-
nally goes into the eye. This is transmitted-light
microscopy.
Many microorganisms in water, many plan
components and the smallest animal parts
are already transparent in nature. Others have
to be prepared. We may make them transpar-
ent through a treatment or penetration with
the right materials (media), or by taking the
thinnest slices from them (using our hand or a
specimen slicer), and then examine them. You
can read more about this in the following sec-
tions.
How do I make thin specimen slices?
Only do this with the supervision of your par-
ents or another adult.
As I already pointed out, the thinnest slices
possible are taken from an object. In order to
get the best results, we need some wax or par-
affin. It is best if you get a candle. Place the
wax in a pot and heat it carefully over a low
burner. Now, dip the object in the liquid wax a
few times. Then, let the wax get hard. Using the
Specimen slicer (19) or a knife/scalpel, cut the
smallest slices from the object that is covered
with wax. These slices are to be laid on a slide
and covered with a cover slip.
How do I make my own specimens?
Take the object that you want to observe and
place it on a glass slide (17). Then, add a few
drops of distilled water on the object using a
pipette. Now, place a cover slip vertically at the
edge of the drop of water, so that the water runs
along the edge of the cover slip. Then, slowly
lower the cover slip over the water drops.
Note:
The included glue “gum media” (18b) is used
to make permanent prepared specimens. Use
this in place of the distilled water. If you want
to keep the object in place on the slide perma-
nently, use the gum media.
Experiments
Now that you’re familiar with your microscope’s
functions and how to prepare slides, you can
complete the following experiments and ob-
serve the results under your microscope.
How do You Raise Brine Shrimp?
Accessories (from your microscope set):
1. Shrimp eggs
2. Sea salt,
3. Hatchery,
4. Yeast.
The Life Cycle of Brine Shrimp
Brine shrimp, or “Artemia salina,” as they are
called by scientists, have an unusual and interest-
ing life cycle. The eggs produced by the female
are hatched without ever being fertilized by a
male shrimp. The shrimp that hatch from these
eggs are all females. In unusual circumstances,
e.g. when the marsh dries up, the male shrimp
can hatch. These males fertilize the eggs of the
females and from this mating, special eggs come
about. These eggs, so-called “winter eggs,” have
a thick shell, which protects them. The winter
eggs are very resistant and capable of survival
if the marsh or lake dries out, killing off the en-
tire shrimp population. They can persist for 5-10
years in a “sleep” status. The eggs hatch when
the proper environmental conditions are repro-
duced. These are the type of eggs you have in
your microscope set.
