Biological Microscopes

A User’s Guide to Biological Microscopes

Ever since its invention in the early 17th century, microscopes have played a huge role in aiding scientists, doctors, and researchers with their various quests. Biology is one of those fields where microscopes have been greatly used. Thanks to microscopes, more information has been discovered aboutcell structure, parts, interactions, and its other essential aspects. If you have a keen interest in biology, purchasing a biological microscope can definitely be considered a valuable investment for you.

How Biological Microscopes Work

Most biological microscopes used today are compound microscopes. This means that users will have the benefit of using two lenses instead of just one. The second lens was added to magnify the view provided by the first lens. In the past, simple biological microscopes could only magnify an object up to more 266 times but compound light microscopes are now able to magnify objects from 1000 to 2000 times.

How to Use Biological Microscopes for Beginners

Step One Look for an ideal place for your biological microscope. Any table with firm even surface would do. If you’re outside, you need to look for a flat area. Extra surrounding space is good to allow you to make drawings and take notes in comfort regarding the images provided by your microscope. Make sure that the excess cord of your biological microscope is put out of sight and harm’s way so you or anyone else won’t accidentally trip on it and cause the microscope to fall.

Step Two Switch on the lamp or light source inside your biological microscope. Light is what allows images to be visible and magnified. Look for the knob controlling your biological microscope’s disc diaphragm. If you’re using an iris diaphragm, look for a lever instead. Either way, the diaphragm controls how much light passes through the metal apertures. More light actually means lesser visibility so be careful on how much light you use.

Step Three Set your objective to low power. It’s easier to scan images this way rather than adjusting down from high power. With objectives set at low power, you’ll also have the benefit of a wider FOV or field of view.

Step Four Place the glass slide containing your sample or specimen. This is, assuming of course, that you already know how to correctly make a dry or wet mount or stain your slide if necessary. Use the stage clips to keep your glass slide in place. Now, start moving the slide while looking at it through the microscope’s objective lenses. Do so until you find the ideal position for it.

Step Five Start adjusting the coarse focus knob. This is the larger knob and it controls the mechanical movement of your microscope’s body tube and where your slide is kept in place. Slowly adjust the knob to have the slide move to the appropriate direction. In time, however, you’ll use less of the coarse knob and more of the fine knob but for now, it’s easier for you to start adjusting with the coarse focus knob.

Step Six Move on to the fine focus knob. Slowly adjust until you can see the image clearly. You can improve the brightness level by going back to the diaphragm and readjusting the amount of light used. To make light adjustment easier, you could start again from the top or using the greatest amount of light used then gradually lessening until you reach optimal light levels.

Step Six Start scanning the slide. An overview is best done with the biological microscope set at low power. If you’re looking for details, that’s the time to set it at high power.

Step Seven Start rotating the nosepiece to increase magnification. Every time you increase magnification, you will have to change your biological microscope’s focus as well. Adjust the lighting using the diaphragm again. You’ll have to repeat the same steps as you continue changing magnification.

Step Eight This last step is only appropriate if your biological microscope is using a 100x oil-immersion lens. If it is, you’ll have to place one to two drops of immersion oil on top of the slide’s coverslip. Afterwards, set the microscope at the highest power before moving the lens into position and until it gets into contact with the immersion oil. Be careful when adjusting the coarse and fine knobs. When you’re done observing the specimen, wipe off the oil from the slide and clean the slide and lenses using the appropriate materials.

Biological microscopes are very expensive but vital to your work. Consider purchasing them secondhand if you really need to take one with you at field exercises.