Lab Manual - eScience Labs

Lab 4: Introducon to the Microscope
7. With the object is in general focus, rotate the revolving nosepiece to the low-power
lens (the next longest). Aer focusing with the course adjustment knob, switch to the
fine adjustment knob to obtain more precise and greater detail. It may also be necessary
to adjust the light, because more light reduces contrast (sharpness).
8. To become familiar with the mechanical stage knobs around the base of the microscope
(if present), turn one slowly to the right, nong that the image will be moving
toward the le. This image inversion is caused by the lenses.
9. If you need higher magnificaon, slowly rotate the high-power lens into place (the next
longest lens). This will bring the p of the lenses very close to the slide.
10. Make sure the objecve lens does not touch the slide.
11. Whenever you use the high-power lens, only use the fine adjustment knob. If the object
was well focused while viewing with the low-power lens, very lile adjustment
should be necessary.
12. If you cannot bring the object into focus, return to the low-power lens, focus the object,
and then return to the high-power lens.
13. When finished, move the revolving nosepiece to the scanning objecve lens posion
before removing the slide.
How to Prepare a Wet Mount Slide
1. To make a wet mount for a specimen that is not already in liquid, take a clean slide and
place the specimen in the center.
2. Add a drop of water.
Note: For cells that are transparent, it may be necessary to add a small drop of stain as
opposed to water.
3. Carefully add a coverslip by placing one end down and slowly lowering the other end.
Note: If the coverslip is added too quickly, large air bubbles may become trapped which
can cause difficulty viewing the slide. If this happens, gently remove the coverslip, add
another drop of water and try again.
4. Remove excess liquid on the boom of the slide or around the edges before it is placed
on the microscope to avoid damage to the lens. Just touch a ssue to the edge of the
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