Lab 2: Use and Care of the Microscope

1
Lab 2 Use and Care of the Microscope
2
The Microscope

• A device used to magnify objects that are too
  small to be seen with the naked eye
• Simple Microscope one lens (like a magnifying
  glass)
• Compound Microscope two or more sets of
  lenses

Simple Compound
3
Important Terms for the Microscope

• Specimen the object that is being looked at
• Ocular lens eyepiece
• Objective lens lens closest to the specimen
• Condenser lens that concentrates the light for
  better resolution of the specimen
• Iris diaphragm controls the amount of light
• Rheostat controls intensity of light
• Course adjustment used for focusing with low
  power objective lens
• Fine adjustment used for focusing with high
  power and oil immersion lens
• Parfocal specimen will remain in focus as you
  change the objective lenses
• Resolution the ability of the lenses to reveal
  fine detail

4
Parts of a Compound Microscope
5
Magnification on a Compound Microscope

• Compound microscopes have 3-4 objective lenses
• Scanning (4x), low power (10x), high power dry
  (40x), and oil immersion (100x)
• The ocular lens (eyepiece) has a magnification of
  10x.
• To determine the total magnification you multiply
  the ocular lens magnification (10x) times the
  objective lens (4x) to get a total of 40x
  magnification.

6
Determining Total Magnification
7
Magnification on a Compound Microscope

• Oil Immersion To use a 100X objective lens, a
  drop of oil is placed between the specimen and
  the scope in order to decrease bending of the
  light rays (refraction).

8
How does a microscope work?
9
(No Transcript)
10
Basic Bacteria Morphologies
11
Assignments for this week

• Lab Report Use of the Microscope
• Record all 3 microorganisms at 10X, 40X, and 100X
  (draw on the back of the lab report page)
• Answer question 1