How to Use a Microscope

Summary

In this instructional video, Mr. Willhelm introduces students to the essential parts and functions of a compound light microscope. He covers how to properly use the microscope, explaining the eyepiece, objectives, stage, diaphragm, and light source, as well as how to adjust for clear focus using the coarse and fine adjustment knobs. Emphasizing correct handling and storage, Mr. Willhelm ensures students understand the importance of each part, such as the objective lenses and stage clips, and provides step-by-step guidance on preparing slides and adjusting light levels for optimal viewing. The video concludes with tips on microscope care and safety.

Takeaways

• 😀 The eyepiece is where you look through to see the magnified image; it magnifies the image 10 times.
• 😀 Objectives are the lenses on the microscope that magnify the image at different levels: low power (4x), medium power (10x), and high power (40x).
• 😀 The stage is where you place the specimen slide, and it has stage clips to hold the slide in place.
• 😀 The diaphragm controls the amount of light passing through the specimen on the stage; it has five different-sized holes.
• 😀 The coarse adjustment knob is used for rough focusing, while the fine adjustment knob is used for fine-tuning the focus to get a sharp image.
• 😀 The light source illuminates the specimen to make it visible through the eyepiece.
• 😀 Always begin by setting the stage to its lowest position before adjusting the objective lenses.
• 😀 The microscope should always be used with the correct amount of light. Ensure the light is on and the diaphragm is adjusted for optimal visibility.
• 😀 When changing objectives, always do so by looking from the side to avoid damaging the lenses or stage.
• 😀 To focus on higher magnifications (medium or high power), use the fine adjustment knob only after the image is roughly focused with the coarse adjustment knob.
• 😀 When storing the microscope, always set it to low power with the stage lowered, turn off the light, and wrap the cord properly to ensure it remains in good condition.

Q & A

What is the purpose of the eyepiece on the microscope?

The eyepiece is where you look through to see the magnified image. It magnifies the image 10 times.

What are the three types of objectives on the microscope, and what is their magnification power?

The three objectives are: Low Power (4x magnification), Medium Power (10x magnification), and High Power (40x magnification).

How do you calculate the total magnification of an image viewed through the microscope?

The total magnification is calculated by multiplying the magnification of the eyepiece (10x) by the magnification of the selected objective lens. For example, with the low power objective (4x), the total magnification is 40x (10x * 4).

What is the function of the diaphragm on a microscope?

The diaphragm controls the amount of light passing through the specimen. Adjusting it helps in getting the right visibility for different specimens.

What should you do if you cannot see anything through the microscope?

Make sure the light source is turned on, and the diaphragm is adjusted properly. If the light is off or the diaphragm is set incorrectly, it can make it impossible to see the specimen.

What is the purpose of the coarse adjustment knob?

The coarse adjustment knob is used to make large focusing adjustments, helping to bring the image into rough focus.

Why should the fine adjustment knob be used after the coarse adjustment knob?

The fine adjustment knob is used for making small, precise adjustments to get the image into sharp focus after using the coarse adjustment knob for rough focus.

Why is it important to look from the side when switching to a higher magnification objective?

Looking from the side ensures that the objective lens does not hit or damage the stage or the slide when switching to a higher magnification objective.

What is a prepared slide, and how is it used in a microscope?

A prepared slide is a slide that has a specimen already placed on it, like frog skin, and is used for viewing under the microscope. It is placed on the stage for observation.

What should you do before storing the microscope?

Before storing the microscope, lower the stage, switch to the low power objective, turn off the light source, unplug the microscope by the plug (not the cord), and carefully store it by wrapping the cord around the storage area.