Obtain a picture of an oil immersion microscope. Such a picture can be found online or in a biology textbook. The pictures are often provided in lab manuals to help you review and improve your laboratory techniques. Examine the overall structure of the microscope.
Look at the top of the microscope. The part of the device that you look through is called the eyepiece. If there is a single eyepiece, then it is a monocular microscope. If there are two eyepieces, then the microscope is binocular. Draw a line from the eyepiece, and label it as an "eyepiece."
Observe the rotating portion of the oil immersion microscope that is below the eyepiece. This structure is the nose piece. It is attached to the objective lenses.
Compare and contrast all of the objective lenses. Each lens has a different magnification. There may be a 10x, a 20x and a 40x. These are the regular, or dry objectives. The oil immersion lens typically has a higher magnification. It might be 100x. Also, the oil immersion objective might have a black band at the bottom.
Observe the platform where you place the slides. This is the stage of the oil immersion microscope. The clips that hold the slide in place are known as the stage clips.
Examine the circular structure beneath the stage. This is known as the diaphragm. It controls the amount of light that you are exposing to the specimen.
Differentiate between the coarse and the fine adjustment knobs. These knobs are located to the sides of the stage. The coarse adjustment is the larger knob, and it moves the stage up and down. The fine adjustment is the smaller knob. Movement of the stage with this knob is not easily observed because it is in such small amounts.
Label the bottom of the oil immersion microscope. The bottom is the base. You can also label the light, which is on the base of the microscope.