The microscope is an essential first line tool in the clinical microbiology lab. It is used to obtain some basic information about the clinical sample: Is there more than one organism in the sample? What is their shape and arrangement? How does the organism(s) respond to standard stains such as the gram stain? This information is important for the microbiologist in deciding what further tests are appropriate in identifying the organism. There is considerable fiscal pressure to do the minimum number of tests necessary.
You will be using bright-field illumination in this lab. There are several other microscopy techniques used in clinical or research labs. Chapter 3 of your text has an excellent section on the different types of illumination, under what conditions are they most useful and what organisms they help identify. Carefully read the section in the book on the principle of how bright-field microscopy works. Where does the light come from, how is it focused on the specimen, how do you determine the actual magnification of the specimen you are looking at.
This lab focuses on the practical aspects of using the microscope for microbiology. This should be a review of what you learned about the microscope in your previous biology labs.