A compound microscope is an optical microscope that uses light and different lenses to exaggerate or magnify an object. To know more about a compound microscope, its basics, and uses in various fields, read on…

Did You Know?

Using a compound microscope, an image can be magnified 2,000 times larger than what is visible to the naked eye.

Among all the numerous inventions till date, the microscope has indeed been one of the most remarkable and significant. Elements too small to be seen by the naked eye can be clearly seen with utmost ease and in great detail because of a microscope.

The term microscope can be split into two separate words, ‘micro’ and ‘scope’, where the term ‘micro’ means small or tiny, and ‘scope’ means to view or to observe. Therefore, a microscope can be understood as an instrument to observe tiny elements.

What is a Compound Microscope?

The word compound means multiple, mix, or a combination of both. A compound microscope is a microscope which uses more than one lens. Devised with a system of combination of lenses, a compound microscope consists of two optical parts, namely the objective lens and the ocular lens. The objective lens uses short focal length to enlarge an image. Therefore animal cells, plant cells, protozoa, bacteria can be easily viewed and studied with the help of a compound microscope.

A compound microscope can be categorized into an upright microscope and an inverted microscope. An upright microscope is just like an ordinary microscope with the lens system, followed by the stage where the specimen is kept, and then the light source. An inverted microscope, as the name suggests, is upside down. It is exactly the reverse replica of the upright microscope with the illumination system first, followed by the stage, and then the lens system.

A compound microscope can be used for varied purposes like medical research and education. It is, however, essential to know the basics of a compound microscope and remember them when in use.

Parts of a Compound Microscope

A compound microscope consists of the objective lens, the eyepiece, the stage on which the specimen is placed, and the adjustment knobs. It also includes a source of light – a mirror, a nosepiece, and an arm. The following diagram will help you understand the microscope better.

Basics of a Compound Microscope

Learning the basics of a compound microscope, so as to associate with it every time it is used, would prove favorable. Following are a few important points that need to be thoroughly understood.

❒ For every microscope to function there needs to be a source of light that would help illuminate the object that has to be seen.

❒ The source of light can either be a mirror, which would reflect light from outside, or the device may have its own light source.

❒ The lower lens, that is the lens closest to the specimen, is called the objective lens. Also known as the primary lens, it magnifies the specimen. There could be objective lenses varying in power. The magnification values may vary from 5x to 100x. The values are written on the side of the lens.

❒ The lens closest to the eye of the viewer, that is the upper lens, is termed as the ocular lens. Also known as the secondary lens, the magnification powers of the upper lens may range from 2x to 20x.

❒ The object lens must be parallel  to the eyepiece. The object lens can be set by rotating the nose-piece, also known as a turret. A ‘click’ sound states that both, the object lens and the eyepiece are positioned in the right place.

❒ Multiplying the magnification of the ocular lens with the magnification of the objective lens results in the total magnification, that is the enlarged image of the specimen.

❒ Thus a 10x ocular lens in concurrence with 30x objective, will result in the magnification factor of 300x. This means that the specimen will be enlarged 300 times larger than when visible to the naked eye.

❒ However, a compound microscope can magnify elements up to a maximum of 2000x only. It is important to note that any image larger than 2000x would neither be recognized by the eye nor would the brain be able to process the image.

❒ In order to picture the specimen in different magnifications, rotate the object lens in lieu with the eyepiece.

❒ Never touch the surface of the lens with your hands as it could blur the lens. It can also account for scratches, thereby reducing the visibility of the specimen by the viewer.

❒ Remember to hold the arm and the base of the microscope simultaneously as a compound microscope is heavier and larger in size. They are also more expensive as compared to other microscopes.

Uses of a Compound Microscope

In this new age of science and technology, a microscope has been a great boon to the world. Let us now consider certain uses of a compound microscope.

▣ Blood analysis is undertaken, which is of immense help in diagnosing illnesses. Thus, a compound microscope is of great use in pathology labs so as to identify diseases.

▣ Various crime cases are detected and solved by drawing out human cells and examining them under the microscope in forensic laboratories. The presence or absence of minerals can be determined, and the presence of metals can be identified, thereby aiding in solving crimes.

▣ Forensic experts and scientists can also find out the country from which a particular drug has come by viewing its particles under a compound microscope.

▣ Students in schools and colleges are benefited by the use of a microscope for conducting their academic experiments. It is of immense help as the students can now see the bacteria and virus, which is otherwise invisible to the naked eye. Thereby they witness things which they have studied in theory.

▣ Plant cells are examined and the microorganisms thriving on it can be ascertained with the help of a compound microscope. Thereby, a compound microscope has proved beneficial to biologists too.

Zacharias Janssen  invented the first compound microscope in the year 1590, and later Galileo Galilei, the great Italian physicist came up with his self-made version. Anton Van Leeuwenhoek, the father of microscopy, is credited with the constant progress made in the field of microscope design and use.

Having absorbed the meaning, basics, and the uses of a compound microscope, you may now be able to identify with the instrument when in use. To comprehend better, always take the assistance of an expert in the field of science. Hope the article has given you a clear picture about a compound microscope.