INTRODUCTION
A microscope
is an example of instrument that we use
to see microorganisms that are too small to be seen. Microorganisms is an
organisms that cannot be seen by naked eyes. So, the microscope is used to
examine this and in the same time, in order to study the sizes and shapes of
living microorganisms, the wet mount methods is used. This method is used
because it is quick,easy, does not require any special equipment and also
enable us to determine if cells are motile. On the other hand, microscope was
early made in 1590 in Netherlands. There are many types of microscopes that
uses light to image the sample such as compound, digital, and fluorescence but
most frequently microscope is used to view the microorganisms is light
microscope. There are many parts in microscope that makes the microscope
functioning :
1)
Eyepiece lens: lens that used to look the specimen. The power lens
have 2 types that are 10x and 15x.
2)
Stage: platform that has hole at the mddle to allow light from
illuminator to pass through the slide contain specimen and it is adjustable.
3)
Objective lenses: is used to magnify the specimen into particular
lenses power in order to obtain the best view. There are 3 to 4 objectives
lenses that are 4x, 10x, 40x, and 100x.
4)
Arm: to supports the eyepiece lens holder on the base.
5) Illuminator:
a steady light source that used in place of a mirror.
6) Coarse and Fine focus: to adjust the stage to get the excellent
image view.
7) Condenser: to focus light from illuminator direct to the specimen.
8) Nosepiece turret: holds two or more objective lenses and can be
rotated to easily change power.
9) Iris diaphragm: is used to vary the intensity and size of the cone
of light that is projected upward into the slide.
How to use a
microscope ?
1. When moving your
microscope, always carry it with both hands. Grasp the arm with one hand and
place the other hand under the base for support.
2. Turn the revolving
nosepiece so that the lowest power objective lens is "clicked" into
position.
3. The microscope slide
should be prepared with a coverslip or cover glass over the specimen. This
will help protect the objective lenses if they touch the slide. Place the
microscope slide on the stage and fasten it with the stage clips. It is also
can be push down on the back end of the stage clip to open it.
4. Look at the objective
lens and the stage from the side and turn the coarse focus knob so that the
objective lens moves downward or the stage, if it moves, goes upward. Move
it as far as it will go without touching the side.
5. Now, look through the
eyepiece and adjust the illuminator for the greatest amount of light.
6.
Slowly turn the coarse adjustment so that the objective lens goes up from the slide. Continue until the image
comes into focus. Use the fine adjustment, if available, for fine focusing.7. Move the microscope slide around so that the image is in the center of the field of view and readjust the mirror, illuminator or diaphragm for the clearest image.
8. Now, you should be able to change to the next objective lenses with only minimal use of the focusing adjustment. Use the fine adjustment, if available. If you cannot focus on your specimen, repeat steps 4 through 7 with the higher power objective lens in place. Do not allow the objective lens to touch the slide.
9. The proper way to use a monocular microscope is to look through the eyepiece with one eye and keep the other eye open to helps avoid eye strain. If you have to close one eye when looking into the microscope, it is not a problem. Remember, everything is upside down and backwards. When you move the slide to the right, the image goes to the left.
10. Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses.
11. When finished, raise the tube or lower the stage, click the low power lens into position and remove the slide.
12. Always keep your microscope covered when not in use.
Care of the microscope.
·
Everything on a good
quality microscope is unbelievably expensive, so be careful.
·
Hold a microscope firmly
by the stand, only. Never grab it by the eyepiece holder, for example.
·
Hold the plug (not the
cable) when unplugging the illuminator.
·
Since bulbs are
expensive, and have a limited life, turn the illuminator off when you are done.
·
Always make sure the
stage and lenses are clean before putting away the microscope.
·
NEVER use a paper towel,
a kimwipe, your shirt, or any material other than good quality lens tissue or a
cotton swab (must be 100% natural cotton) to clean an optical surface. Be
gentle! You may use an appropriate lens cleaner or distilled water to help
remove dried material. Organic solvents may separate or damage the lens
elements or coatings.
·
Cover the instrument
with a dust jacket when not in use.
·
Focus smoothly; don't
try to speed through the focusing process or force anything. For example if you
encounter increased resistance when focusing then you've probably reached a
limit and you are going in the wrong direction.
OBJECTIVE
·
Learn
to use a simple bright-field microscope correctly.
·
To
provide an experience in the use of microscope.
·
To
illustrate the diversity of cells and microorganisms.
RESULTS
1) Stained
cells
Penicillium spp.
 |
Figure 1:
40x magnification
|
 |
Figure 2
: 100x magnification
Figure 3
: 400x magnification
|
Saccharomyces
cerevisiae
Figure 4
: 1000x magnification
Lactobacillus fermentum
Figure 5
: 1000x magnification
DISCUSSION
Penicillum spp. is
a type of multicellular species. It is a gram-negative bacteria because it has
stain with pink colour. The filamentous structure can be seen under 40x
magnification under the microscope. The characteristics of this Penicillum spp. are nutrition mycelium
colorless, pale, or with distinctive colors. It has hyphae with the diaphragm
which is the diaphragm are conidiophores, smooth or rough. Base without enough
cells, the formation of enlargement is not top of the top capsule, the conidiophore
after several branches will resulting in several rounds of symmetrical or
asymmetrical small stems that are shaped like a broom. Conidia spherical, oval
or short cylindrical, smooth or rough, when most of the growth of blue-green. A
few species have closed the capsule shell.
Wet
mount methods is made by several liquids but usually water,immersion oils and
glycerols is used. Water is really needed to make them but for some wet mounts,
immersion oils will be used. Immersion oils is used in order to see the tiny
specimen that hardly can be seen under the microscope besides the living and
moving specimen can also be observed.
First specimen for the
wet mount methods is Saccharomyces
cerevisiae. It is classifies in fungi kingdom. This is because it has acell
wall made of chitin and it has no peptidoglycan on its cell walls.Saccharomyces cerevisiae are able to
break down its food through both aerobic respiration and anaerobic
fermentation.They get their energy from glucose. They can survive in an oxygen
deficient environment for a period. They also able to have both sexual and
asexual reproduction.In asexual reproduction, the haploid of the yeast under
goes mitosis and form more haploid yeasts. Then, these haploid yeasts, one from
each strain will fuse together to form cell.The nuclei of both cell will fuses
together and now, they will form zygote. The
diploid cell can go through mitosis which called budding.Another four
more zygotes or they can go under meiosis and from an ascus which will split
into four ascospores.Then, these haploids can undergo germination.
The
second specimen for the wet mount methods is Lactobacilli fermentum. It is rod-shaped and straight. But under
the certain conditions, they also can form spiral or coccobacillary. They are
often found in pairs or chains of varying length. Lactobacilli fermentum is a gram-positive bacteria. They are also classified
as lactic acid bacteria, and derive almost all of their energy from the
conversion of glucose to lactate during homolactic fermentation. In this
process, 85-90% of the sugar utilized is converted to lactic acid. They
generate ATP by nonoxidative substrate-level phosphorylation.
CONCLUSION
There
are two types of bacteria that are gram-positive and gram-negative bacteria.
For gram-positive bacteria, they have thick cell wall of peptidoglycan which is
stain with purple colour. Example of gram-positive bacteria is Lactobacilli fermentum. For gram-negative
bacteria, they have thin cell wall and no peptidoglycan which is stain with
pink colour.Example of this gram-negative bacteria is Penicillum spp. .
This
report has identified the correct way to view sample of microorganisms by using
the microscope. Different species of microorganisms was observed under
different magnification to examine the structure and size of microorganisms.
REFERENCE
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