Setting Up and Using a Compound Light Microscope

Setting Up and Using a Compound Light Microscope

Setting Up a Compound Light Microscope

General Introduction

  • A compound light microscope uses light to illuminate the specimen that is then magnified by two lenses.

Steps for Using the Microscope

  • Start by cleaning the lenses of the compound microscope with lens paper to ensure clear images. Don’t use any other materials as they may scratch the lens.
  • Plug in the microscope and turn on the light source.
  • Place the slide with the specimen onto the stage and secure it using the stage clips.
  • Start with the lowest power objective lens in place.
  • Use the coarse adjustment knob to move the stage as high as it will go but don’t let the slide touch the objective lens.
  • Look through the eyepiece and use the coarse focus knob to move the stage downwards until the image comes into focus.
  • Refine the image using the fine focus knob for a sharper image.
  • Once focused, you can switch to the higher power objective lenses. Remember always use the fine adjust focus when changing to higher power objective lenses.

Viewing the Specimen

  • Adjust the diaphragm to control the amount of light reaching the specimen to create contrast which makes details easier to see.
  • Always make minor adjustments to the fine focus knob and to the diaphragm for the best image.
  • Remember never use the coarse focus knob when a high power objective lens is in place as it can damage the lens or the slide.

After Use

  • Lower the stage, remove your slide, and return the lowest power objective lens into position.
  • Turn off the light, cover the microscope and return it to storage properly.

Interpreting the Image

  • Remember that images viewed under a microscope are upside down and backwards.
  • Images are also shown in 2D, whereas cells are actually 3D structures.
  • Keep in mind that a microscope only shows a small part of the specimen so you may need to move the slide around to find an area of interest.
  • Field of view gets smaller when you switch to higher power lenses and depth of focus becomes thinner.

Important Safety Precautions

  • Never touch the glass part of lenses with your fingers. Hold the microscope by the arm and support the base as you carry it.
  • Be cautious when using the microscope around water. Never use it with wet hands or near a wet bench.
  • Never force any mechanical part of your microscope.
  • Always store the microscope in its proper place after use. Always store with the low power lens clicked into position and remove the slide from the stage before storing. The microscope should be covered and carried with two hands.