1. The Compound Light Microscope, Parts and functions
Salman bin Abdulaziz University
College of Pharmacy
Clinical Pharmacy Department
Physiology-I (Practical Part)
[PHL215]
The Compound Light Microscope, Parts and functions
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2. After completing this lecture, you should be able to:
Mention the different types of microscope.
Name the different parts of the compound microscope and explain the functions of each.
Know the proper procedures for cleaning and preparing microscopes for use and returning them to their assigned storage place in proper condition and how to use the compound microscope.
Name the precautions that must be observed during and after using the microscope.
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3. Commonly Used Microscopes
Compound Binocular
Light Microscope
Compound Monocular
Light Microscope
Dissecting Microscope
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4. Cont'd… Scanning electron microscope (SEM).
Transmission Electron Microscope (TEM).
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5. Uses of Commonly Used Microscopes
Notes
Magnification power
Uses
Microscope Type
Does not provide space for dissection of materials being examined.
Generally provides total magnification from 40X to 1000X.
Used to view tissue and blood samples for the diagnosis of disorders and disease.
Compound Light
Microscope (Binocular or Monocular)
Provides space between stage & objectives for dissection.
Generally provides total magnification from 10X to 45X.
Used by scientists to dissect larger tissue samples and small animals to aid in diagnosis.
Dissection Microscope
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6. Cont'd… Notes Magnification power Uses Microscope Type
Images are high-quality and detailed.
TEMs are large and very expensive.
It produce two dimensional picture.
TEMs can magnify a sample up to one million times.
Can image morphology of samples, e.g. view sections of material, fine powders suspended on a thin film, viruses or bacteria.
Transmission Electron Microscope (TEM).
Can produce images of high resolution, greater clarity and three dimensional pictures.
Generally provides total magnification from 25X to 250,000X but most specimens are easier to view at magnification less than X. 
A SEMS can detect and analyze surface fractures, provide information in microstructures, provide qualitative chemical analyses
Scanning electron microscope (SEM).
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7. Parts of the Microscope
A. The support system:
(1)Base, (2) Pillar, (3) Handle,
(4) Body tube (7) Fixed stage, and
(8) Mechanical stage
B. The focusing system:
(5) Coarse adjustment screw,
and (6) Fine adjustment screw,
C. The optical (magnifying) system:
(9) Fixed and revolving nose pieces,
(10) Objective lenses, and (13) Eye-piece
D. The illumination system:
Source of light, (11) Mirror, and
(12) Condenser.
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8. Parts of the Microscope
A. The support system:
The support system functions as a framework to which various functional units are attached:
i. Base. It is a heavy metallic, U- shaped base or foot, which supports the microscope on the worktable to provide maximum stability.
Base
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9. Parts of the Microscope
ii. Pillar. is attached to the handle. The inclination joint allows the microscope to be tilted at a suitable angle for comfortable viewing.
Inclination joint
Inclination joint
Pillar
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10. Parts of the Microscope
iii. Handle (the arm or limb). The curved handle, which projects up from the Inclination joint supports the focusing and magnifying systems.
It is used for safe transportation of the microscope.
Arm
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11. Parts of the Microscope
iv. The Stage.
1. Stage: Platform on which microscope slide are placed for viewing.
2. Slide holder: hold the slide in place & secures slide to the mechanical stage.
3. Mechanical Stage: Used for adjusting the position of the slide for viewing.
4. Mechanical Stage control knobs: Move the slide. 1 3 2 4
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12. Parts of the Microscope
B. The Focusing System
It is employed for raising or lowering the optical system with reference to the slide under study till it comes into focus. Thus, the adjustments place an objective lens at its optimal working distance, i.e. its focal length.
i. Coarse adjustment used when making large changes in focus on the microscope.
ii. Fine adjustment used when changing small amounts of focus.
Some microscopes only have ONE adjustment knob so, it is a course adjustment.
Coarse adjustment
Fine adjustment
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13. Parts of the Microscope
The Optical (Magnifying) System
The optical system consists of the body tube, the eyepiece, and the nosepiece that carries the objectives. It can be raised or lowered as desired.
i. Eyepiece. The eyepiece fits into the top of the body tube and it has magnification power of 10X.
Eyepiece
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14. Parts of the Microscope
ii. Body Tube. Fitted at the upper end of the handle, either vertically or at an angle, the body tube is the part through which light passes to the eyepiece, thus conducting the image to the eye of the observer. It can be raised or lowered by the focusing system.
Body tube
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15. Parts of the Microscope
iii. The nosepiece. It is fitted at the lower end of the body tube and has two parts: the fixed nosepiece, and the revolving nosepiece. The latter carries interchangeable objective lenses. Any lens can be rotated into position when desired, its correct position being indicated by a ‘click’.
iv. Objective lenses (also called objectives, or; simply ‘lenses’).
Low-power (LP) Objective (10 × )
High-power (HP) Objective (45 ×)
Oil-immersion (OI) Objective (100 ×)
Scanning Objective (3 ×)
Nosepiece
Objective lenses
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16. Parts of the Microscope
D. The Illumination (Lighting) System
The illumination system must, therefore, provide uniform, soft, and bright illumination of the entire field of view. Two factors are involved in providing such uniform illumination:
i. The construction and position of the condenser.
ii. The size of the iris diaphragm (Used to vary the amount of light which passes through the slide).
The illumination system of the compound microscope consists of: a source of light, and a mechanism to condense the light and direct it into the specimen under study.
i. Source of light. The light source may be outside the microscope or within the microscope.
Source of light
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17. Parts of the Microscope
ii. The mirror. is used to reflect light from a light source up through the diaphragm.
Mirror
iii. The condenser (‘Substage’ or ‘substage condenser’). The condenser is a system of lenses fitted in a short cylinder that is mounted below the stage.
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18. Parts of the Microscope
iv. Diaphragm
Used to vary the amount of light which passes through the slide.
Usually better in lower amounts
Diaphragm 18
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20. PRECAUTIONS AND ROUTINE CARE
Select a chair of suitable height so that your eyes are at a level slightly above the eyepiece. This will ensure comfortable working for long periods.
Ensure that all the lenses are clean and free from dust and smudges. Do not touch them with your fingers, nor blow on them to remove dust. (Only use lens paper/muslin cloth for cleaning )
Check the position of the objective, condenser, and diaphragm, to ensure optimal illumination.
Never lower any objective from any height while looking into the microscope.
Cover the microscope with the plastic cover after use.
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21. Microscope Transport
Always with one hand on the arm & one on the base.
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22. Preparation for Use Transport microscope to work station
Remove dust cover
Plug in microscope
Inspect and clean microscope
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23. Preparation for Storage
Replace dust cover
Return microscope to storage area
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24. Preparation for Storage
Clean microscope
Rotate shortest objective (4X) into place over stage
Lower stage for max distance between objective & stage
Wrap cord around base or on cord hanger

25. Do You Have Any Questions?
Thank You
For
Listening
Do You Have Any Questions?
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