THE MICROSCOPE

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THE MICROSCOPE

• PARTS
• AND
• FUNCTIONS

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WHAT IS A MICROSCOPE?

• A microscope is a tool used by biologists to
  magnify and observe very small structures.
• Microscopes use lenses to magnify objects

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Types of Microscopes

• In a light microscope, light passes through the
  object being looked at.
• A stereomicroscope is used for viewing large
  objects, such as insects, through which light
  cannot pass.

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Electron Microscopes

• Electron microscopes use a beam of electrons to
  magnify objects more than 500,000 times.

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Transmission electron microscopes shows internal
details of a specimen
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Scanning electron microscopes show the surfaces
of a specimen in 3 dimensions.
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Parts of the Microscope
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Parts of the Microscope

• A. Eyepiece (or Ocular lens) Contains a 10X
  lens. What you look through.
• B. The body tube goes from the eyepiece to the
  lenses.

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• C. Arm Connects the base and the upper part of
  the microscope. Always grasp this and the base
  when carrying the microscope
• D. nosepiece Part that contains the lenses

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• E. The low power (10X) objective lens. Used to
  magnify the image.
• F. High power objective lens. The magnification
  is 40 or 43X.
• (look at the lens and check!)

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• G. Course adjustment Used to focus the image
  under low power.
• H. Fine adjustment used to focus the image
  under high power.

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• I. Stage Where you place the slide or
  specimen. There is an opening for light to pass
  through to the eyepiece.
• J. Stage clips Hold the slide containing the
  specimen on the stage.

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• K. Diaphragm. Used to adjust the amount of
  light going through the specimen.
• L. Light source. A lamp or mirror is used to
  direct light from the base through the hole in
  the stage and through the specimen.

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• M. Base The bottom support of the microscope.
  Always hold this when carrying the microscope.

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HOW DO YOU DETERMINE THE TOTAL MAGNIFICATION OF
THE SPECIMNEN?
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TO DETERMINE TOTAL MAGNIFICATION

• MULTIPLY THE MAGNIFICATION OF THE EYEPIECE
  (OCULAR) TIMES THE OBJECTIVE lens.

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• Total magnification using the low power
• 10 x 10 100x
• Total magnification under high power
• 10 x 43 430x

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USING THE MICROSCOPE IS AS EASY AS 1, 2, 3

• 1. CENTER THE SLIDE ON THE STAGE AND USE THE
  SCANNING LENS (4X) TO LOCATE THE SPECIMEN THROUGH
  THE EYEPIECE.
• FOCUS USING THE COURSE ADJUSTMENT

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• 2. SWITCH THE OBJECTIVE TO LOW POWER AND FOCUS
  USING THE COURSE ADJUSTMENT
• 3. SWITCH THE OBJECTIVE TO HIGH POWER AND FOCUS
  USING THE FINE ADJUSTMENT.