the microscope

1. Microscope
-Sir Leomered P. Medina

2. MICROSCOPE
A microscope is an instrument used to see
objects that are too small for the naked eye.
The science of investigating small objects using
such an instrument is called microscopy.
Microscopic means invisible to the eye unless
aided by a microscope.

3. Parts and Functions of a
Compound Microscope

4. Light Microscope
Uses single lens
Uses set lenses or a
lens system
SIMPLE COMPOUND

5. Simple Light Microscope

6. Compound Microscope

7. Compound Microscope
Mechanical Parts Magnifying Parts Illuminating Parts
Adjustments
and Support
Enlarge the
specimen
Provide the
light

8. Mechanical Parts
o Base
– Bottommost portion that supports the
entire/lower microscope
o Pillar
– Part above the base that supports the other
parts
o Inclination Joint
– Allows for tilting of the microscope for
convenience of the user

9. Inclination Joint
Pillar
Base

10. o Arm/Neck
– Curved/slanted part which is held while
carrying the microscope
o Stage
– Platform where object to be examined is
placed
o Stage Clips
– Secures the specimen to the stage
Mechanical Parts

11. o Stage Opening
o Body Tube
– Attached to the arm and bears the lenses
o Draw Tube
– Cylindrical structure on top of the body tube
that holds the ocular lenses
Mechanical Parts

12. Draw Tube
Stage
Body
Tube
Arm /
Neck

13. o Revolving Nosepiece
– Rotating disc where the objectives are
attached
o Dust Shield
– Lies atop the nosepiece and keeps dust from
settling on the objectives
Mechanical Parts

14. Dust Shield
Revolving
Nosepiece

15. o Coarse Adjustment Knob
– Geared to the body tube which elevates or
lowers when rotated bringing the object into
approximate focus
o Fine Adjustment Knob
– A smaller knob for delicate focusing bringing
the object into perfect focus

16. Coarse
Adjustment
Knob
Fine
Adjustment
Knob

17. • Condenser Adjustment Knob
– Elevates and lowers the condenser to
regulate the intensity of light
• Iris Diaphragm Lever
– Lever in front of the condenser and which is
moved horizontally to open/close the
diaphragm
Mechanical Parts

18. Iris Diaphragm
Lever
Condenser
Adjustment Knob

19. Illuminating Parts
o Mirror
– Located beneath the stage and has concave and
plane surfaces to gather and direct light in order to
illuminate the object
o Electric Lamp
– A built-in illuminator beneath the stage that may eb
used if sunlight is not preferred or is not available

20. Mirror /
Electric Lamp

21. MAGNIFYING PARTS
• Ocular / Eyepiece
– Another set of lens found on top of the body
tube which functions to further magnify the
image produced by the objective lenses. It
usually ranges from 5x to 15x.

22. Ocular/ Eyepiece
Objectives

23. MAGNIFYING PARTS
• Objectives
– Metal cylinders attached below the nosepiece and
contains especially ground and polished lenses
• SCANNER
• LPO / Low Power Objective
– Gives the lowest magnification, usually 10x
• HPO / High Power Objective
– Gives higher magnification usually 40x or 43x
• OIO / Oil Immersion Objective
– Gives the highest magnification, usually 97x or
100x, and is used wet either with cedar wood oil or
synthetic oil

24. Total Magnification
Magnification = Objective lens X Eyepiece lensMagnification = Objective lens X Eyepiece lens
e.g. What is the total
magnification if the objective lens
is twenty times (X20) and the
eyepiece lens five times (X5)?
Magnification = 20 X 5 = X100

25. Asmagnification increases,detail
increases but
Onion cell
40x
Onion cell 100x
Onion cell 400x
less of the cell is seen

26. Caring for the Microscope
1. Do not let any liquids to come in contact with
the microscope.
2. Always store the microscope inside a box
after use.
3. Return the objective lens onto low power after
use.
4. Carry the microscope by the arm.
5. Use a soft clean tissue to wipe the lenses

27. Microscope
slides
Coverslip
s

28. Preparing a
slide as a wet
mount.

29. Useofstains
 some parts of a plant cell can be clearly
seen when the cell is mounted in water
 E.g. an Elodea leaf cell:
 cell wall
 several chloroplasts

30.  other cell structures which are not so
obvious can often be shown up more clearly
by the addition of dyes called STAINS
Iodine Solution
Used to stain plant
cells
Methylene Blue
Used to stain animal
cells

31. A thin inner layer of
epidermis is peeled
off.
Snapping leaf
backwards exposes
the epidermis.
Epidermis is placed on
slide & covered with 2-3
drops of distilled water .
Coverslip is lowered.
A drop of stain is put
at one end of slide.
1
An onion is cut
into quarters.
2
One of the fleshy scale
leaves is removed.
3
5
4
6
7
Stain is drawn over
specimen using a small
piece of filter paper.

32. How to make a wet-mount slide …
1 – Get a clean slide and coverslip from your teacher.
2 – Place ONE drop of water in the middle of the slide. Don’t use
too much or the water will run off the edge and make a mess!
3 – Place the edge of the cover slip on one side of the water drop.
You do not need to use the stage clips
when viewing wet-mount slides!
5 – Place the slide on the stage and view it first with the red-banded
objective. Once you see the image, you can rotate the nosepiece to
view the slide with the different objectives.
4 - Slowly lower the cover slip on top of the drop.
Cover
Slip
Lower slowly

33. Appearance of the Specimen
Objects appear upside-down&backward
Movementappears tobein oppositedirectionthan actual
movement 1 2
moveslide
slideappearstomove
2 1

34. End
-Sir Leomered P. Medina