Lab 1' Microscopy

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Lab 1. Microscopy
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Microscope

• Microbiology study organisms too small to be seen
  with the naked eye
• Father of microscopy Anton van Leeuwenhoek
  (1632-1723)
• First to describe bacteria
• Any two dots that are closer together than 0.275
  micrometers will be seen as a single dot
  (resolution)
• Any object smaller than 0.275um will be invisible
  (magnification)
• 1000um 1mm

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Microscope

• Base
• Stage (where you put the slide)
• Arm
• Light source, condenser
• Diaphragm ? modify light going through contrast
• Objectives lenses 4X, 10X, 40X, 100X
• Ocular or eyepieces 10X
• Objective X ocular total magnification

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Microscope anatomy
http//shs.westport.k12.ct.us/mjvl/biology/microsc
ope/microscope.htm
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How to use

• Carry with both hands one hold the arm the other
  the base
• Plug it in, turn on
• Use the focus knob to take the stage away from
  the objective when you put the slide on
• Secure the slide with the clamps
• Look first using 4X objective
• Focus using the large knob (coarse) and then the
  small knob (fine)

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How to focus

• Coarse adjustment at 4X using the coarse knob,
  fine knob for final touch
• Once everything is in focus you can switch to
  higher objective
• If lose focus go back to previous magnification
• Troubleshooting cant focus
• Lens dirty ? use lens cleaner paper
• practice

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.

• Again always focus with low power first
• Go from 4X to 10X to 40X to 100X
• You need oil for 100X objectives (we will do this
  next week)
• Turn the light off if you are not using the
  microscope

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What not to do

• Hold the microscope by the arm only
• Try to focus at high power first
• Use oil at 100X and then go back at 40X (oil get
  sucked up in the 40X lens and very hard to clean)
• Put the slide on without lowering the stage

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Wet mount

• Suspend the yeast preparation swirl it gently
• Transfer a small drop on the slide using the
  pipette
• Place a cover slip on top
• Put on the stage (coverslip up, slide underneath)
  ? observe
• manipulate slide and cover slip by their
  sides

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Wet mount
www.sporeworks.com/ labnotes/microscopytek.html
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Yeast

http//www.lima.ohio-state.edu/academics/biology/i
mages/yeast.jpg

• http//fig.cox.miami.edu/cmallery/255/255hist/yea
  st.jpg

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Hanging drop slide

• Place a ring of Vaseline around the edge of a
  coverslip
• Using the pipette place a drop of the Artemia in
  the center of the coverslip
• Place the depression slide on the coverslip
• Turn the slide over

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Hanging drop slide
Source Case, 2004
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Remember the Objectives of the laboratory 1

• Learn how to focus
• Look at 1 histology slide ? draw your observation
  at 2 magnification
• Make wet mount of yeast ? draw your observation
• Hanging drop slide of water with artemia cyst ?
  draw your observation
• Everybody has one microscope ? find a lab partner
  for next time
• Record lab results in the notebook
• Dont forget to sign the sheet about lab rules