essential details regarding microscope, usage and type of microscope from simple type of microscope discovered in early time

1. MICROSCOPE
Session 2

2. Learning Objectives
• Define the Microscope
• Explain the principle of microscope
• List type of the microscope
• Identify the major parts of the microscope and
their respective functions
• Explain safety precautions of the microscope
• Describe proper use of the microscope.
• Describe the limitations of Microscope
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3. Activity ; Brain storming
• What is microscope?
• Is microscope equipment or instrument?
• What are the parts of microscope?

4. Definition of terms
• Microscopy is the technical field of using
microscopes to view objects that can not be
seen by naked eyes.
• It is the science of using microscope.
• Microscope is a magnifying equipment,
magnifies minute objects making them visible
to the eye.
• It is an equipment used to see minute objects
that can not be seen by naked eyes.
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5. Principle of the Microscope
• Minute objects invisible to naked eyes are
illuminated to create images and then the
images are magnified to make them visible
to the eye.
• This is ; an object placed on stage magnified
through the objective lens and when is
focused , a magnified image can be
observed though ocular lens

6. Models of microscope
1. Monocular microscopes which have only
one eyepieces.
2. Binocular microscopes which are made
with two eyepieces.

7. Monocular Binocular

8. Types of microscope
• There are different microscopes depending on
the purpose for which it is intended.
• They can also be classified based on their image
making physical principles, area of application
and versatility.
• However the microscopes can easily and
comfortably divided into TWO Major types;
• Optical/Light microscope
• Electron microscope

9. Types of microscope Cont…
• Optical/Light Microscopes
• These are the types of microscope which uses
light as a source of energy to generate image
and glass lenses for magnification of image.
• Under this category there are three subtypes;
i. Simple microscope
ii. Compound microscope
iii. Dissection/Stereo microscope

10. Types of microscope Cont…
i. Simple microscope
• This is the microscope which has a daylight
mirror , use daylight/sunlight as source of
energy to generate image.
• Have only one glass lens for magnification of
the object image.

11. Types of microscope Cont…
ii. Compound microscope
• This is the microscope which uses inbuilt light
sources to generate image.
• This has two different optical parts for
magnification of object images.
- Objective lens and
- Eyepiece lens

12. Types of microscope Cont…
• Compound microscope are the most
commonly used in many laboratories
because they are;
- Efficient
- Inexpensive
- Magnify objects as 2000 times the
original size
• Are used to study cells, chromosomes and
DNA

13. Types of microscope Cont…
iii. Dissection/Stereo microscope
• This is a light microscope which allows an
observer to view objects in three dimension (3D).
• It contains lens in different angle that provides a
three dimensional viewing of objects for
complete diagnosis.
• However, it does not have high magnifying power
like the compound microscope.
• It is mainly used in studying of dissection parts of
living organisms

14. Types of microscope Cont…
• Electron microscope
• Electron microscopes works on the same
principle as an optical microscope but uses
electrons to generate image in the place of
light and electromagnets to magnify in the
place of glass lenses.
• This has much higher resolution than the
optical microscope.

15. Types of microscope Cont…
• Electron microscope is the most advanced
type of microscope used in modern science.
• It is powered by a beam of electrons that
strikes an object to magnify it.
• It is used for studying
- Cells
- Small particles of matter and
- Large objects

16. Types of microscope Cont…
Types of Electron microscope
–There are two major types
i. Transmission Electron Microscope (TEM)
ii. Scanning Electron Microscope (SEM)

17. Types of microscope Cont…
i. Transmission Electron Microscope (TEM)
• It is used for studying cells and tiny slices of
microorganisms like viruses, after they have
been stained with gold and placed upon a
wire grid.
• It gives two dimensional view of object.
• It has high magnifying power than SEM

18. Types of microscope Cont…
ii. Scanning Electron Microscope (SEM)
• This is used to provide three dimensional
viewing of objects.
• It has lower magnifying power than TEM

19. Parts of microscope

20. Name of part Function
Eyepieces Upper end magnifying lens
Objectives Brings the object into focus at a shorter distance
Revolving Nose piece For quick exchange of objective
Mechanical stage Specimen stage
Specimen slide holder It holds slide in correct position
Condenser Adjust correct position of front lens for
illumination of large object
Diaphragm Adjusts the light intensity from the light source in
relation to the objective
Fine and course adjustment Proper focusing
Tube, Mono/Binocular Light transmission media
Light source Bottom light the slide mounted specimen
Base Equipment holder
Parts of microscope Cont…

21. Care of the Microscope
• Do not clean objective by xylene or ethanol
(lenses will stuck)
• Never use ordinary paper to clean lenses
• Never touch lenses with your fingers
• Never clean support or stage with Xylene or
acetone
• Never clean inside lenses of eyepiece or
objectives with cloth or paper (This might
remove the antireflective coating); use a fine
paintbrush only.

22. Care of the Microscope Cont…
• Never leave the microscope without eyepieces
unless the opening is covered
• Never keep the microscope in a closed
wooden box in hot humid countries
• Never press the objective onto the slide, since
both slide and objective may break.
• Take care during focusing
• Keep the mechanical stage clean

23. Care of the Microscope Cont…
• Do not leave microscope with immersion oil
on the objective remove oil after daily use.
Mild soap solution is suitable for most
cleaning
• Always use voltage stabilizer this is for those
areas with voltage fluctuations
NB: Adhere to Bio safety precautions on
handling biological specimen

24. Proper use of the microscope
• Always follow the manufacturer’s instructions.
• Place the microscope on a firm bench, free from
vibration.
• Switch on the light source.
• Adjust the eyepieces by sliding them horizontally
until both eyes fit comfortably and the two fields
merge.

25. Proper use of the microscope
Cont…
• Centre the condenser as follows:
- Swing the x10 objective into position
- Raise the condenser to the uppermost
position
- Open the iris diaphragm fully
- Open the light diaphragm to illuminate
the whole field
• Clean and dry the underneath of a glass slide
by wiping with lens tissue.

26. Proper use of the microscope Cont…
• Rotate the nosepiece so that the x 10 objective is
in position. Slight resistance is felt as the
objective moves into the correct position.
• Place the slide carefully on the stage.
• Never place the slide on the stage when the x 40
or x 100 objectives are in position, to prevent
scratching of the lenses.
• Adjust the illumination:
- Control light intensity by using the light
control
- Reduce the iris diaphragm to control
brightness

27. Proper use of the microscope Cont…
• Focus the specimen by racking the stage
carefully upwards with the x10 objective in
position.
• Using the coarse adjustment knob, rack
downwards slowly until the image
• comes into view. Use the fine adjustment
knob to focus the image sharply.
• Swing the x 40 or x100 objectives into position
to examine in more detail.

28. Proper use of the microscope Cont…
• After examination, lower the stage or swing the
lowest power objective into position before
removing the slide.
• Never remove the slide when the x 40 or x 100
objectives are in position as this may scratch the
lenses.
• Wipe off any oil from the lenses using a piece of lens
tissue and microscope stage using a piece of cloth
soaked in detergent
• Switch off the microscope, disconnect from the
power source and cover to protect from dust

29. Limitation of the microscope
• They only use day light for those with mirror and
• They only use electricity for those with inbuilt
light source.
• They only use beam of electrons for electron
microscopes.
• Not used beyond the manufacturer’s instructions
• In case of breakdown consult responsible
personnel

30. Summary
• A microscope is an instrument that is used to
magnify small objects
• Major types of microscope are light(optical)
and electron microscopes
• For well function of microscope must be kept
clean and aligned
• Always when transport microscope use both
hands, one hold arm and supported under
the base by other hand.

31. Evaluation
• Define the Microscope
• Principle of microscope
• List type of the microscope
• The major parts of the microscope and their
respective functions
• Safety precautions of the microscope
• Proper use of the microscope.
• The limitations of Microscope

32. References
• F.J. Baker, R.E. Silverton, Introduction to Medical
Laboratory Technology, 7th
Edition,( 2001) Oxford University Press;
• Monica Cheesbrough – Medical Laboratory Manual for
Tropical Countries Volume I,
2nd Edition (1981) Butterworth & Co (Publishers) Ltd
• Monica Cheesbrough-District Laboratory Practice in
Tropical Countries Part 1 & 2
(2002) Cambridge University Press.
• Standard Operating Procedures- Care and
Maintenance of Laboratory Equipment-By
AMREF (T)