Using the Microscope

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Using the Microscope
2012-01-22 14:27:37
Lab Tech

Lab Tech
Show Answers:

  1. What is a monocular microscope?
    • one eye piece
    • less expensive
  2. what is a dissecting microscope used for?
    larger objects because it only magnifies 30-90x
  3. what kind of microscope do we use?
    binocular light microscope
  4. how do you pick up your microscope?
    one hand on the handle and the other hand on the bottom
  5. what should you do before using the microscope?
    • clean lenses
    • clean oculars
    • wipe lenses dry
  6. how do you clean the lenses?
    wipe any oil from objective with cotton-tipped applicator with alcohol. clean all objectives
  7. what material can you use to wipe clean the lenses and oculars?
    dry cotton-tipped applicator or lens paper
  8. what are the different types of lights?
    • tungsten (less expensive)
    • halogen (brighter, more expensive)
  9. what is an ocular?
    eye piece
  10. how much does an ocular magnify?
  11. what is interpupillary distance?
    the distance between your eyes
  12. what are the different objectives?
    • 4x
    • 10x
    • 40x
    • 100x
  13. which objective do we use for oil immersion?
  14. which objective is the scanning objective?
  15. which objective is low power?
  16. which objective is high power?
  17. what is magnification?
    ocular x objective
  18. what is the mechanical stage?
    holds the slide with stage clips
  19. how can you move the stage?
    with coarse and fine focus knobs
  20. what is the condenser?
    focuses light on the object
  21. what will happen if you move the condenser dow?
    it will increase the depth of field
  22. what happens to the brightness of the field when you move the condenser down?
    decreases the brightness
  23. what is the iris diaphragm?
    alters the amount of light reaching the object
  24. where is the iris diaphragm located?
    within the condenser
  25. what happens when you open the iris diaphragm?
    increases the amount of light
  26. what happens when you close the iris diaphragm?
    decreases the amount of light
  27. what objective should you start with when viewing a slide?
  28. whare are the steps to the correct use of the microscope
    • turn it on
    • set interpupillary distance
    • place slide on stage between clips
    • start with 10x objective
    • bring into focus
    • adjust condenser and diaphragm to give depth of field and correct light penetration
  29. how do you bring a slide into focus?
    start with the stage in highest position, move stage down until the slide comes into focus
  30. what are the three ways to adjust the amount of light?
    • turn rheostat up
    • open diaphragm
    • move condenser up
  31. do unstained objects need more light or less light?
    less light
  32. if there is too much light, what should you do?
    • turn down rheostat
    • close diaphragm
    • drop condenser down
  33. what should you do when you have the scope on low power (10x)?
    evaluate: staining if stained, cellularity, distribution
  34. what do you do for fecals?
    scan the entire slide at low power
  35. how do you focus a slide when it's on 40x or 100x?
    using the fine focus knob only!!
  36. when do you use oil immersion?
    blood smears and cytology
  37. how do you use oil immersion?
    • place drop of immersion oil on slide
    • move 100x objective into place
    • adjust using the fine adjustment only!
  38. how big is the average dog RBC?
    7 microns
  39. describe low power
    • see large field of view
    • objects only magnified 100x
    • see less detail
    • requires less light than higher power
  40. describe high power
    • smaller hole
    • smaller field of view
    • more light needed
    • objects appear larger
    • total magnification is 400x
  41. what do you do when you are ready to put away your microscope?
    • wipe oil from objective with cotton-tipped applicator with alcohol
    • clean all objectives
    • wipe objectives dry using dry cotton-tipped applicator or lens paper
    • clean oculars
    • place 4x objective down
    • unplug, fold cord, stage down to hold cord
    • place dust cover over scope and put away
  42. Defin ocular lens
    eye piece
  43. Define objective lens
    the part that magnifies either 4x, 10x, 40x, or 100x
  44. Define mechanical stage
    the part where the slides sits and can move up and down to focus
  45. Define stage clips
    holds the slide in place
  46. Define course focus
    moves the mechanical stage up and down...only move in 4x or 10x
  47. Define fine focus
    moves the stage up and down to focus...move at 40x or 100x
  48. Define condenser
    • focuses light on the object
    • increases or decreases the depth of field
    • increases or decreases brightness
  49. Define iris diaphragm
    controls how much light reaches the within the condenser
  50. Define light source
  51. Define stage control knobs
    moves the stage sideways
  52. Define rheostat
    controls light
  53. Define power switch
    turns on the microscope
  54. List three ways to increase the amount of light passing through the slide
    • turn up the rheostat
    • raise the condenser
    • open the iris diaphragm
  55. List two things that affect the amount of light passing through the slide.
    • stained or unstained
    • thickness
  56. What materials can be used to clean lenses and objectives?
    • dry cotton applicator (q-tip)
    • lense paper
  57. On what power is it okay to use the course adjustment knob?
  58. What is meant by inter-pupillary distance?
    the distance between the eyes
  59. What's a micrometer?
    • 1,000th of a millimeter
    • the measurement we use when using the microscope
  60. How can a red blood cell be used in lieu of a micrometer?
    a dog's RBC is 7 micrometers so we use that as a comparison to the other RBC's
  61. What happens to the field of view as you change from a 10x objective to a 40x objective? What about vice versa?
    the field of veiw decreases
  62. Which objective should you use immersion oil?
  63. Which part of the microscope controls the depth of field?
  64. What is the total magnification achieved with a 10x ocular and a 40x objective?
  65. How should the immersion oil be cleaned from the microscope?
    with alochol and a dry cotton applicator or lense paper
  66. What is the purpose of the condenser?
    • changes depth of field of view
    • regulates the light reaching the slide
  67. How should the condenser be set for viewing a wet prep of urine?
  68. How should the condenser be set for viewing a fecal float?
  69. How shold the condenser be set for viewing a dry-prep of a blood smear?
  70. What effect will moving the condenser downward have on the brightness you see?
    decreases the brightness
  71. What does the iris diaphragm do?
    regulates the amount of light
  72. How do you properly put the microscope away?
    • clean oculars and objectives
    • make sure it is set on the 4x objective
    • put the stage all the way down
    • wind up the cord
    • place dust cover over the microscope
    • store it in the cabinet
  73. What is the major benefit of halogen lights
    they are brighter and have truer light
  74. What is the major advantage of tungsten lights?