Micro Lab Experiment 1

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Micro Lab Experiment 1
2011-06-26 22:08:11
micro lab

Bright field light microscope
Show Answers:

  1. What is the proper way to carry a microscope?
    With both hands, one under the base and the other holding the arm
  2. Explain what the working distance is for the microscope?
    the distance between specimen and tip of objective lens when in focus
  3. What is the function of immersion oil? What properties immersion oil have?
    • - to fill the space between the objective lens and the specimen
    • -increase refractive index
    • -reduce the lost of light
  4. What is an ocular micrometer? What is it used for?
    • - a small circular glass disk on which uniformly spaced lines of unknown distance ranging from 0-100 are etched
    • -used for measuring microorganism after it is calibrated
  5. What is a stage micrometer? What is it used for?
    • -a circular disk is mounted on a glass slide, the disk has informly spaced lines of known distance etched on it.
    • -use to calibrate a ocular micrometer
  6. Briefly explain how you calibrate a microscope in order to measure bacteria. Indicate what equipment you would need.
    • microscope, ocular micrometer, stage micrometer
    • -super impose the scale of ocular micrometer over the scale of the stage micrometer at 0 on the left of the scale.
    • -read the scale to the right until aligned on ocular micrometer is exactly super imposed on the line with stage micrometer.
    • -count the number of spaces on the stage micrometer that are between the super imposed lines on the ocular micrometer.
    • -Do the math to determine one ocular space
  7. What are a condenser and an iris diaphragm?
    • -condenser- focuses the light on a small area above the stage
    • -iris diaphragm- controls the amount of light that enters the condenser
  8. What happens to the lens at the tip of the objective as magnification increases?
    As the magnification increases the size of the lens at the tip of objective becomes progressively smaller
  9. Why is oil necessary when using the 100x objective?
    To fill the working distance between the objective and the specimen to minimize the lost of light to increase resolution.
  10. Why is it necessary to calibrate the ocular micrometer with each objective? Each microscope?
    • -The magnification is different for each objective lens.
    • -The numerical value holds only 4 specific objective ocular lens combo
    • -The ocular space changes with each objective change so each microscope is different.