THE PARTS OF THE MICROSCOPE: UNDERSTANDING MICROSCOPY

Light microscopy is a general term used for any type of microscopy where light is being transmitted from a source which is on the opposite side of the sample, to the objective lens. Generally, the light is passed through a condenser to focus it on the sample to have maximum brightness. After the light has passed through the sample, it goes through the objective lens to magnify the image of the sample & then to the oculars, where the enlarged image is viewed.

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Microscope
Light microscopic techniques have significantly developed over the past 20 years & now provide an indispensable tool to study molecular events at subcellular level in order to gain temporal & spatial information at high resolution. To achieve optimal results, it is essential to carefully plan & carry out microscopy-based experiments, which requires the understanding of at least the basics of cell biology, sample preparation & fluorescence light microscopy.

1. The Compound Microscope Parts and Functions

2. Learning Competency: Identify the parts and functions, and demonstrate proper handling and storing of a compound microscope

3. What part of the microscope should you hold when carrying it? a) The base and the arm b) The stage c) The eyepiece d) The objective lenses

4. Which part of the microscope is used to adjust the focus on the specimen? a) The arm b) The coarse and fine focus knobs c) The base d) The illuminator

5. 3. What is the function of the objective lens on a compound microscope? a) To support the microscope slide b) To reflect light towards the eyepiece c) To magnify the specimen for viewing d) To adjust the amount of light passing through the specimen

6. 4. When storing the microscope, what position should the objective lenses be in? a) The highest power objective lens should be clicked into place b) The lowest power objective lens should be clicked into place c) Any objective lens can be clicked into place d) The objective lenses should be removed

7. 5. Which part of the microscope allows you to change between different objective lenses? a) The stage b) The eyepiece c) The nosepiece d) The diaphragm

8. The correct answers are: a) The base and the arm b) The coarse and fine focus knobs c) To magnify the specimen for viewing b) The lowest power objective lens should be clicked into place c) The nosepiece

9. Microscope A  microscope  is an instrument that produces enlarged images of small objects, allowing the observer to closely examine minute structures that are otherwise too small to be seen by the naked eye.

10. Here are some key points about microscopes: 1. Optical Microscopes: Definition: Optical microscopes use glass lenses to magnify objects. They are the most familiar type of microscope.

11. Uses: Biological Research : Scientists use optical microscopes to study cells, tissues, and microorganisms. Medical Diagnosis : Doctors use them to examine blood samples, diagnose diseases, and identify pathogens. Education : Microscopes are essential tools in schools and universities for teaching biology and other sciences.

12. Types of Optical Microscopes: Compound Microscope : Consists of multiple lenses (objectives and ocular) and uses visible light. It can magnify up to 2,000×. Darkfield Microscope : Creates a white specimen against a black background by scattering light. Fluorescence Microscope : Uses ultraviolet light to view fluorescently labeled specimens. Contrast/Phase Microscope : Examines structures inside cells using different refractive indexes

13. Parts of the Compound Microscope The compound microscope has three main parts: Magnifying parts Illuminating parts Mechanical Parts

14. Magnifying Parts The magnifying parts are used to enlarge the view of specimens. It includes the following: Objective lens Ocular lens / Eyepiece

15. 1. Objective Lens The most important of the optical parts. Commonly, there are three or four objective lenses: Scanner low power objective (LPO) high power objective (HPO) oil immersion objective (OIO)

16. OBJECTIVE LENS

17. Objective Lens Scanner – marked with a red line and the shortest among the other objective and is usually marked 4x. low power objective (LPO) – marked with a yellow line and usually have a magnification power 10x. It locates and shows the structure of the specimen.

18. high power objective (HPO) – is a long and slender and is usually marked 40x or 60x. It shows the detailed structure of the specimen. oil immersion objective (OIO) – is a special type of objective lens; it may be long or short. It is used to increase the resolution of microscope. It has a small lens at its end that is usually marked 99x or 100x. A drop of cedar oil is used on the specimen before it is viewed under the lens. Objective Lens

19. 2. Ocular lens / Eyepiece Magnifies the image formed by the objectives. It is attached to the upper end of the microscope and usually marked 5x, 10x, 15x or 20x.

20. Illuminating Parts The illuminating parts are used to supply light to the slide on the stage. Following are these parts: Mirror Numerical Aperture Condenser Iris Diaphragm

21. 1. Mirror - collects and reflects light from an external light source up into the microscope. It has adjustable sides that may be plain or concave. 2. Numerical aperture - measures the microscope’s ability to gather light an resolve fine details of a specimen at a fixed distance.

22. 3. Condenser - directs the maximum amount of light upon an object. 4. Iris Diaphragm - a flat disc located beneath the condenser. It has an adjustable opening or aperture hat may be reduced or enlarged to any size by adjusting its lever.

23. Mechanical Parts The mechanical parts are used to support and move parts of the microscope. Following are these parts: Arm 7. Revolving nosepiece Stage 8. Base Stage Clips 9. Inclination joint Body tube Draw tube Adjustment knobs

24. 1. Arm - the bent or curved structure that supports the stage and body tube. 2. Stage - the platform where the slide is placed. 3. Stage Clips - hold the prepared slide firmly on the stage.

25. 4. Body tube - holds the draw tube and connects the eyepiece to the objectives. 5. Draw tube - houses the ocular lens. It is fitted inside the upper end of the body tube. 6. Adjustment Knobs - bring the objects into focus so that the view of the specimen appears sharp and clear.

26. 7. Revolving nosepiece - supports the objectives and enables them to be positioned in the desired place. 8. Base - anchors the microscope firmly on the table. 9. Inclination joint - allows the upper part of the microscope to be bent.