1.5.2 Handling and using a light microscope

Key Concept:

Proper handling and use of the light microscope ensures accurate observations of microscopic specimens and prevents damage to the instrument or injury to the user.

Short Notes:

The light microscope is a delicate instrument that must be handled carefully to function properly. When carrying the microscope, always use both hands—one holding the arm and the other supporting the base. Place it on a flat surface, plug in the light source or adjust the mirror, and ensure the stage and lenses are clean before use.

To use the microscope, start with the low-power objective lens and center the specimen on the stage. Adjust the light using the diaphragm, and bring the image into focus with the coarse adjustment knob. Then use the fine adjustment knob for a clearer view. Avoid using the coarse knob under high power to prevent damaging the slide or lens. After use, clean the lenses with lens paper, turn off the light, and cover the microscope to protect it from dust.

Key Terms:

• Focus – To adjust for a clear image,
• Coarse adjustment – Large knob for rough focusing under low power,
• Fine adjustment – Small knob for sharp focusing under high power,
• Lens paper – Special paper used to clean microscope lenses,
• Stage clip – Part that holds the slide firmly on the stage.

Example:

In Ethiopian science classrooms, students learn to observe teff pollen under a microscope by starting with low power and using both adjustment knobs correctly.

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