A microscope is a device that magnifies an image allowing you to see small structures in detail. While they come in a variety of sizes, the ones used at home and school often have similar parts: a base, an eyepiece, a lens, and a platform. Knowing the fundamentals of using a microscope will allow the equipment to be well protected and provide you with a valuable research tool.
Part 1 of 3: Assembling the Microscope
Step 1. Know the components of the microscope
The microscope has many essential parts that you must identify and use properly. The eyepiece is where you will see the specimen. Simple microscopes only have one eyepiece while more complex ones have a binocular. Here are the components of a microscope:
- The platform is where you will place the slide.
- The arm is the part that connects the base to the eyepiece.
- There are two focus knobs: Coarse Focus and Fine Focus. The first is usually large, sits on the side of the microscope and moves the objective lens toward or away from the slide. It also allows you to find the specimen and roughly focus on it. The fine focus knob is smaller and is used to specifically focus on the specimen. It allows you to view it in greater detail.
- The lens is the part that enlarges the image. There are several lenses with different types of magnifications.
- The light source is located at the base and points towards the platform. Its function is to provide light to be able to visualize the image.
- The diaphragm is located just below the platform and allows you to modify the amount of light that shines on the image.
Step 2. Place the microscope on a clean, flat surface
Clean up any debris on the surface that could damage the microscope. Use a lint-free cloth and cleaner. Make sure the surface is close to an outlet.
- Hold the microscope by the base and arm. Never hold it solely by the latter.
- Place the microscope on the table and plug it in.
Step 3. Have your microscope manual handy
If you want to know the instructions on how to manipulate the specific model of the microscope, please read the manual carefully. There you will also find instructions on maintenance and cleaning if necessary.
- Keep the manual with the microscope for easy reference.
- If you've lost the manual, look for a downloadable version on the manufacturer's website. If you can't find one, contact the company directly and see if they can mail it to you.
Part 2 of 3: Prepare the slides
Step 1. Wash your hands before starting
Hands contain oils that can easily stain slides and specimens. These oils can harm both specimens and the microscope. If you have gloves, it is recommended that you put them on.
Keep your hands and work area as clean and free from contaminating particles as possible
Step 2. Have a lint-free cloth handy to clean and touch the slides
This is a special cleaning material that does not leave lint after cleaning a surface. Many slides are coated on one side to make mounting them easy. This can easily cause dust and other contaminants to collect. Therefore, a lint-free cloth will keep contamination out.
- Never use paper towels to clean the slides, as they leave a lot of lint.
- If you are wearing gloves, you can touch the slide, but try to only touch the sides.
Step 3. Use prepared slides
Prepared slides already have a correctly positioned specimen. You can buy them in science supply stores or you can even find them together with the microscope. Once you have become accustomed to using the microscope, you can prepare your own slide.
- To prepare your own slide, obtain a specimen that you would like to see in more detail. Pond water or pollen are great samples to start with.
- Pour a small drop of the water or place some pollen spores directly on the slide.
- Place a coverslip at a 45-degree angle and drop it onto the slide. The water should hold the slide in place.
- If you want to keep the samples longer, add some clear nail polish to the edges of the slide to fix the coverslip in place.
Step 4. Place the slide on the microscope platform
Lift the slide holding it only by the edges, so you don't get your fingerprints and oils on it, as they can contaminate it. You can also use the lint-free cloth to hold the slide.
If the slide is dirty, wipe it gently with the lint-free cloth
Step 5. Secure the slide in place using the two clips on the platform
On the platform, you will see two clips (metal or plastic) that serve to secure the slide in place so that you can move your hands and focus on the microscope. You should have no problem sliding the slide under the snaps.
- Avoid forcing the slide to go under the snaps. These should be raised slightly to allow the slide to enter. If you're having trouble, try getting it to slide under one at a time. Lift the clasp, slide the slide underneath, and then do the same for the other slide.
- The slides are quite fragile and can break if not positioned properly.
Step 6. Turn on the microscope
The microscope switch is usually located on one side. The center of the slide should be illuminated by a small circle of light.
- If you don't see any light, try adjusting the diaphragm until it's fully open. The diaphragm must have a lever or disc that rotates to modify its diameter and change the amount of light that passes through it. If it's closed, you won't see any beams of light. Move the lever or turn the disc until you see a beam of light going through the slide.
- If you still don't see anything, contact the store where you bought the microscope or ask for help changing the microscope bulb.
Part 3 of 3: Focusing the Microscope
Step 1. Adjust the eyepiece in case you have a binocular microscope
If you only have one eyepiece, you can skip this step. For a binocular microscope, rotate the eyepieces until you find the correct space between the eyes (also known as the interpupillary distance). You should see a single circle of light when looking through both eyepieces.
- If you see two images, you need to keep adjusting the distance.
- Move the eyepieces closer together or farther apart until you see a single circle of light.
- If you wear glasses, take them off. You can use the microscope settings to focus the object according to your sight.
Step 2. Adjust the diaphragm to its maximum aperture
The diaphragm allows you to modify the amount of light on the slide. To start focusing on the specimen, you will need to shine as much light onto the slide as possible. There should be a lever or rotating disk that allows you to change the diameter.
Move the lever or turn the dial until the diaphragm is fully open
Step 3. Start focusing on the smallest magnification target
Maybe you have two or three rotating objective lenses that you can move around to magnify the object. You should start with the 4x objective and increase the magnification until the object is in focus. Generally, the 4x objective (sometimes 3.5x) is the standard norm for the lowest magnification in a basic microscope.
- Low power lens gives you the widest perspective and allows you to focus on the subject slowly without losing sight of it. It is for this reason that it is often referred to as an exploration target. If you start with the lens at high power, you may not see the object or not see it completely.
- The two most common high-power objectives are 10x and 40x.
- The eyepiece has a 10x magnification which is multiplied by the magnification of the objective. Therefore, the 4x objective gives you a total magnification of 40x (10 times 4). The 10x objective gives you a 100x magnification and the 40x objective a 400x magnification.
Step 4. If necessary, move the slide to center it on the platform
Most slides are much larger than the specimen placed on them. If you can see the specimen, try to place it directly in the center of the light source. If you can't see it, slowly move the slide while looking through the eyepiece.
Remember that magnification is reflected, so you will need to move the slide in the opposite direction on the platform to properly fit the lens
Step 5. Focus the slide with the help of the adjustment knobs and the diaphragm
Start with the coarse adjustment knob (the larger of the two knobs), then do the same with the fine adjustment, and lastly, change the light levels. While looking through the eyepiece, slowly turn the coarse focus knob until you begin to see the image.
- Use the fine adjustment knob to focus more on the slide.
- Note that as you focus, the platform gets closer and closer to the target. It is possible to raise it high enough to make contact with some of the objective lenses, so be careful during the focusing process so that this does not occur.
- Adjust the diaphragm under the platform. Reducing the light can make the subject appear lighter and less blurry.
Step 6. Enlarge the image with a higher lens
Switch to a higher lens only when you cannot focus on the subject with a low power one. Higher magnification will allow you to see the specimen in greater detail. Note that not all tall objectives will work with all slides, as some can focus too closely.
- Be careful when changing targets as you could break the slide.
- When working with higher objectives (eg the 10x option), use the fine adjustment knob. Because the coarse focus knob brings lenses closer to the platform, the slide can crack if you're not paying attention.
- Use different objectives and adjust the focus knobs until you feel comfortable with what you see in the microscope. Use different slides to practice more.
Step 7. Put a cover on the microscope when you clean it
Lenses can easily be damaged by dust and other floating particles. Keeping the lens and deck clean of dust will prevent damage. Only clean the lenses with an approved solution and a lint-free cloth.