Microscope, which were created in the 16th century and contain the ability to enlarge microscopic objects like microbial cells, have revolutionised science by producing images containing recognisable as well as distinguishable characteristics.

What are Microscopes?

Microscope Definition

By enlarging an opposing image, microscopes are used in research labs to observe minute objects like cells as well as bacteria. Microscopes are composed of magnification lenses, each of which has a unique magnification capability. Based on the focal strength of the lens, which differs by type, the specimen would be enlarged.

Their ability to function is a result of the precise parts employed in their manufacture that enable devices to achieve high degrees of magnification. They are able to view exceedingly minute specimens and distinguish structural distinctions, like animal and plant cells or bacterial cells, on a microscopic scale.

Microscopes consist of structural parts which support and maintain the microscope as well as its parts, as well as optical components for magnification and monitoring of specimen images. This section explains the parts of a microscope and the responsibilities they perform in enabling specimen visualisation.

Biorender.com was used to make this image.

Figure: A diagram of a microscope’s components

The microscope has three basic components: the head, the base, and the arm.

1. Head:Occasionally, the head is considered the body. It holds the optical components of the upper part of the microscope.
2. Base:The microscope’s base provides great support. It is also equipped with miniature illuminators.
3. Arms: This part of the microscope links the head to the foundation, as well as the eyepiece tube to the base. It is utilised to hold the microscope’s head and to move the instrument. Certain high-end microscopes have an adjustable arm containing numerous hinges, which permits the microscopic head to operate very easily, thus enhancing the spectator experience.

Functions of the optical components of a microscope

Examine, magnify, and produce a picture of a specimen on a slide using the microscope’s optical devices. These are the constituent parts:

1. Eyepiece:An alternative term for the eyepiece is the ocular. This includes the part of the microscope that allows for observation. It is located at the apex of the microscope. There is an alternate eyepiece having magnifications varying from 5 to 30X. The standard magnification is 10x.
2. Eyepiece tube:The eyepiece tube includes the eyepiece holder. The eyepiece is located just over the objective lens. Some microscopes, like binoculars, include a flexible eyepiece tube that can be rotated for optimal vision and range adjustment. They lack any adaptability when it relates to monocular microscopes.
3. Objective lenses:are generally the primary lenses utilised for examining specimens. The magnification varies between 40x and 100x. There are between one and four objective lenses on a microscope, many of which are reverse-facing, as well as others that are forward-facing. Each lens has a unique magnification power.
4. Nose piece:The nose piece is another name for the rotating turret. It is the location where objective lenses are maintained. This could rotate the objective lenses dependent on the lens’s magnification power, as it is movable.
5. Adjustment knobs:They are the knobs used to focus the microscope. Fine adjustment knobs as well as coarse adjustment knobs constitute the two types of adjustment knobs.
6. Stage:The area where the specimen is placed for public observation is known as the stage. Clips on the stage hold the specimen slides in place. The mechanical level is the most famous, as it allows you to manage the slides by adjusting them by using mechanical knobs on the level, as opposed to physically manipulating them.
7. Aperture:A hole on the microscope stage through which light is transmitted from the origin to the stage.
8. Microscopic illuminator:The microscopic illuminator, which is located at the bottom of the microscope, is its source of light. This item replaces a mirror. It gathers light from an external supply of around 100 volts and low voltage.
9. Condenser:These lenses collect as well as focus light from the source towards the specimen. They are located near the diaphragm, beneath the microscope’s stage. They perform a crucial function in the production of crisp, clear images at magnifications of 400X or greater. When the condenser’s magnification rises, the image becomes sharper. Advanced microscopes contain an Abbe condenser with around 1000X magnification.
10. Diaphragm:Iris is an alternative term for the diaphragm. It is situated underneath the stage of the microscope, which controls the amount of light that enters the specimen. The intensity and size of the laser beam that reaches the specimen may be adjusted using this equipment. In high-quality microscopes, the diaphragm is connected to an Abbe condenser, and together they may alter the light concentration as well as the intensity that enters the specimen.
11. Condenserfocus knob: This knob adjusts the light’s focus over the specimen by raising or lowering the condenser.
12. Abbe Condenser— It is a condenser designed particularly for microscopes of superior grade. It is flexible and permits magnifications exceeding 400X. Generally, the numerical aperture of microscopes of superior quality is greater than that of objective lenses.
13. The rack stop:The rack stop controls the space between the stages, avoiding the objective lens from coming too close to the specimen slide, which may be detrimental. Its purpose is to stop the specimen slide from ascending too high and striking the objective lens.

Parts of a Microscope Revision Questions (FAQs)

Q. Define a Microscope.

Ans. Microscopes are instruments that are used in science laboratories, to visualize very minute objects such as cells, and microorganisms, giving a contrasting image, that is magnified.

Q. State functions of a microscope.

Ans. A microscope is usually used for the study of microscopic algae, fungi, and biological specimens.

Q. Differentiate between a condenser and an Abbe condenser.

Ans. Condensers are lenses that are used to collect and focus light from the illuminator into the specimen. They are found under the stage next to the diaphragm of the microscope. They play a major role in ensuring clear sharp images are produced with a high magnification of 400X and above. Abbe condenser is a condenser specially designed for high-quality microscopes, which makes the condenser to be movable and allows very high magnification of above 400X. High-quality microscopes normally have a high numerical aperture than objective lenses.

Q. What is the magnification power of the objective lenses?

Ans. Objective lenses have a magnification power of 40X to 100X.

Q. How does the eyepiece compare to the objective lens?

Ans. The eyepiece, also known as the ocular is the part used to look through the microscope. Its found at the top of the microscope. Its standard magnification is 10x with an optional eyepiece having magnifications from 5X – 30X. Objective Lens are the major lenses used for specimen visualization. They have a magnification power of 40x-100x. There are about 1- 4 objective lenses placed on one microscope, in that some are rare facing and others face forward.

Q. Why is the rack stop included in the microscope from the factory, and can it be replaced?

Ans. Rack stop is included in the microscope for preventing the specimen slide from coming too far up and hitting the objective lens.

Q. What is a magnification power?

Ans. Magnification of a lens is defined as the ratio of the height of an image to the height of an object. Microscope magnification measures the total enlargement of the image of an object. Magnification power is the product of eyepiece lens power and objective lens power.

Q. Differentiate between the fine and the coarse adjustment knobs.

Ans. The coarse adjustment knob moves the stage up and down to bring the specimen into focus. The fine adjustment knob brings the specimen into sharp focus under low power and is used for all focusing when using high-power lenses.

List down the 18 parts of a Microscope.

1. Ocular Lens (Eye Piece)
2. Diopter Adjustment
3. Head
4. Nose Piece
5. Objective Lens
6. Arm (Carrying Handle)
7. Mechanical Stage
8. Stage Clip
9. Aperture
10. Diaphragm
11. Condenser
12. Coarse Adjustment
13. Fine Adjustment
14. Illuminator (Light Source)
15. Stage Controls
16. Base
17. Brightness Adjustment
18. Light Switch

List down the 3 structural parts of a microscope.

1. Head
2. Arms
3. Base

References and Sources

1. Microbiology by Lansing M. Prescott (5th Edition)
2. https://www.pobschools.org/cms/lib/NY01001456/Centricity/Domain/349/TheMicroscope-howtouse.pdf
3. https://sciencing.com/parts-microscope-uses-7431114.html
4. https://www.amscope.com/microscope-parts-and-functions/
5. https://cpb-us-e1.wpmucdn.com/cobblearning.net/dist/3/4204/files/2018/08/Parts-of-the-Microscope-103b21p.pdf
6. https://www.microscope.com/compound-microscope-parts