8 BIOL 1506E The Microscope 2 Turn the nosepiece halfway between the high power

8 biol 1506e the microscope 2 turn the nosepiece

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BIOL 1506E The Microscope 2. Turn the nosepiece halfway between the high power objective (40X) and the oil immersion objective (100X). 3. DO NOT MOVE THE STAGE OR YOU WILL LOSE THE PARFOCAL FEATURE. 4. Add a small drop of immersion oil to the center of the slide. 5. Turn the nosepiece so that the oil immersion objective comes into place. The drop of oil should spread in the space between the slide and the objective. If you have done everything correctly the objective will not hit the slide. NOTE : Use only the fine focus knob to focus the image. Using the coarse focus knob at this point can cause you to break the slide. If once you have moved up to a higher power, you cannot find the area of interest on the slide you probably no longer have it within the new field of view. Try moving the slide to center the area of interest again. 6. Turn the nosepiece halfway between two objectives, then lower the stage. This will prevent breaking the slide or scratching the lens of the objective in case you accidentally bring the stage up instead of down. Remove the slide. 7. Before storing the microscope, clean the slide and the objective lens of oil using a tissue paper (Kim-Wipe) and lens cleaner (95% ethanol). NOTE : When focusing, if the slide gets too far from the objective and you need to bring it closer, always do so by looking from the SIDE. This ensures that you do not hit the slide with the objective. Once the slide is in close proximity of the objective, you can then focus away from the slide while looking through the ocular. Important points to remember! Always use immersion oil with the immersion oil objective (100X) Never get oil on any other lens. Clean up all oil when finished (slide and objective) D. Slides Slides used in the laboratory have an identification label that may have some of the following information regarding the specimen: the common or Latin name of the specimen the part of the specimen on the slide the type of section of the specimen: 9
BIOL 1506E The Microscope cs : cross section (cut transversely) ls : longitudinal section (cut lengthwise) wm : whole mount (not cut at all) smear : tissue is spread on slide, usually done with fluid type tissue e.g. : blood type of stain used You can now view the Dissection Microscope video and the Compound Microscope video found on D2L. Verify your answers to Figure 1 and Figure 2 while watching the video. E. Practical Exercises 1. Field of view and magnification Field of view : the area of a slide visible through the ocular Eyepoint magnification : also called “total magnification” is the power of the objective or drum multiplied by the ocular power. a) Dissection Microscope Measure the diameter of the field of view, using a metric ruler. To do so watch the first part of the Practical Exercises video for an example. Stop the video at the end of “Field of view - Dissection Microscope” and before the start of the “Field of view - Compound Microscope” (at about 1 m 10 sec). Using the pictures from Figure 4 , complete Table 1 .

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