Using a compound microscope allows you to view specimens at a magnified level. Here's a step-by-step guide:
1. Preparation and Setup
- Uncover and Plug In: Remove the microscope from its storage case and unwrap the power cord. Plug the power cord into a reliable power outlet.
- Clean Lenses: Use lens paper to gently clean all glass surfaces, including the objective lenses, eyepiece(s), and condenser lens. This ensures a clear image. Avoid using other types of paper as they can scratch the lenses.
- Turn on the Light Source: Switch on the light source. If your microscope has a mirror instead of a built-in light, adjust the mirror to direct light through the stage opening.
- Place the Slide: Carefully place your prepared slide on the microscope stage. Secure it using the stage clips to prevent movement.
2. Initial Focusing
- Start with the Lowest Power Objective: Rotate the revolving nosepiece to position the lowest power objective lens (usually 4x or 10x) into the light path. This makes it easier to initially locate your specimen.
- Adjust the Coarse Focus: Use the coarse focus knob to bring the stage (or objective lens) as close as possible to the slide without touching it.
- Look Through the Eyepiece(s): While looking through the eyepiece(s), slowly turn the coarse focus knob in the opposite direction to move the stage (or objective lens) away from the slide until the image comes into rough focus.
- Adjust the Fine Focus: Use the fine focus knob to sharpen the image and bring it into precise focus.
3. Optimizing the Image
- Adjust the Condenser: The condenser focuses the light onto the specimen. Adjust its height (usually with a knob below the stage) to optimize the brightness and contrast of the image.
- Adjust the Iris Diaphragm: The iris diaphragm controls the amount of light passing through the specimen. Adjust it to improve contrast and resolution. Closing the diaphragm increases contrast but may reduce brightness and resolution. Opening it does the opposite.
4. Increasing Magnification
- Center the Specimen: Before increasing magnification, center the area of the specimen you want to examine more closely in your field of view.
- Rotate to a Higher Power Objective: Carefully rotate the revolving nosepiece to select a higher power objective lens (e.g., 40x).
- Refocus: Use the fine focus knob to refocus the image. Avoid using the coarse focus knob at higher magnifications, as this can damage the objective lens or the slide.
- Repeat as Necessary: Repeat steps to use even higher power objective lenses (e.g., 100x, often used with immersion oil).
5. Using Oil Immersion (If Applicable)
- Only Use with Specific Objectives: Oil immersion is used with special 100x objective lenses.
- Apply Immersion Oil: Place a small drop of immersion oil directly on the slide where the light shines through.
- Rotate the Objective into Place: Carefully rotate the 100x oil immersion objective lens into the oil.
- Refocus: Use the fine focus knob to bring the image into sharp focus.
- Clean the Lens: After use, clean the objective lens with lens paper and lens cleaner to remove the oil.
6. Completion
- Lower the Stage: Carefully lower the stage before removing the slide.
- Rotate to Lowest Power: Rotate the nosepiece to the lowest power objective lens.
- Turn Off the Light: Turn off the light source.
- Clean the Microscope: Clean the stage and any other areas that may have gotten dirty.
- Store Properly: Replace the dust cover and store the microscope in a safe, dry place.
By following these steps, you can effectively use a compound microscope to explore the microscopic world.
