Microscope general points
Remember that your text cannot substitute for selfstudy. It will also become apparent that you simply cannot randomly view a microscope slide labeled, for example, simple epithelium, and immediate see an image equivalent to what you would see as a text example.
Samples are chosen because there is a predominate tissue or cell type, but this does not exclude others. Second, we have searched slides to find excellent examples of the features we wish to illustrate. Some areas of even professionally prepared slides have artifacts,that is, wrinkles, folds, and areas of poor staining. Consider yourself warned!Although you will not likely spend lots of time at the microscope, the image you see is no better than your ability to handle the microscope and appropriately adjust the light source and various condensers and lenses to get the best, brightest image with adequate resolution.Figure 4.1 (microscope parts and use) and Figure 4.2 (microscope alignment) describe some of the attributes of the typical brightfield microscope and how you can get the most out of the time you spend in laboratories at the microscope. Keys to good microscope use are listed as follows.
Examining Prepared Slides
• Ensure the stage is lowered.
• Place a low-power objective (4 or 10?) in position for initial examination.
• Ensure the slide is clean and the cover-slipped side is face up.
• Bring the specimen into proper focus and orient yourself to the entire sample.
• Close the field diaphragm to ensure proper alignment (see Fig. 4.2).
• Switch to the magnification of choice; if the objectives are parfocal on the revolving nosepiece, only small adjustments should be necessary when changed.
• Be careful not to smash the slide when focusing.
• Always lower the slide stage and place a low-power objective lens in position when you are finished.
• Turn off the power to the light source.
• Use only approved lens paper to clean any lenses.