written by: Leigh A. Zaykoski•edited by: Leigh A. Zaykoski•updated: 3/22/2011
What is a compound microscope? In simple terms, a compound microscope is a high-power microscope that offers greater magnification than a low-power microscope. Learn more about the compound microscope and its parts to better understand its use in medical science.
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The structure of a compound microscope consists of the head, base and arm. The head contains the optical parts used for magnification. The base contains the lighting for the microscope and also supports the microscope. The arm supports the head of the microscope and makes it easy to carry this piece of equipment.
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The microscope contains a number of optical parts, which allow for the magnification and visualization of slides. The eyepiece is what you look through to see your slide. This eyepiece usually has a magnifying power of 10X, but some eyepieces have magnifying powers of 5X to 30X.
Objective lenses range from 4X to 100X and are the primary optical lenses on this piece of equipment. The eyepiece tube holds the eyepieces in place. If the microscope has a binocular head, it may also contain an adjustment ring that makes it easier for people with inconsistencies in eyesight to use the equipment. The nosepiece contains the objective lenses, which are mounted on a rotating part. This allows the user to select different objectives.
Focus knobs allow the user to focus the microscope properly. Some microscopes have separate fine focus and coarse focus knobs. Other models have coaxial knobs, which are the two knobs mounted on the same axis. Coaxial knobs make it easier for the viewer to focus the microscope since only one knob is needed. When using a microscope, you place the specimen on a stage. Some microscopes have a mechanical stage, which allows for very minute slide movements. If the microscope does not have a mechanical stage, it also has stage clips that allow the user to move a slide manually. The illuminator contains the lighting for the microscope.
The iris diaphragm regulates the amount of light that reaches a slide. This part works with the condenser, which collects the light from the illuminator. Both parts help to control the focus and amount of light applied to the slide.
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Medical Science Uses
So, what is a compound microscope used for in medical science? Laboratory analysis, physicians, infection control specialists, pathologists and researchers use the compound microscope to view cells and tissue specimens. This allows them to diagnose infections, identify the presence of cancer, monitor the treatment of diseases and identify abnormal levels of electrolytes, blood cells and toxins in the blood. Looking at cells and tissues under a compound microscope also allows researchers to develop new drugs and treatments for diseases. Researchers can look at specimens to determine the effects of drugs on cancer cells, infections and other medical conditions. This type of microscope also has use in forensic science and criminal analysis, as it allows investigators to magnify specimens taken from crime scenes.