Proper Use of a Microscope

We have all had those days, at one point or another, in the laboratory where it seems that every microscope in the place is broken. You can see the bright red spot on the slide with the naked eye but once under a microscope, it's gone. I can see it, but I can't see it! The problem is not the microscope. As a friend of mine, who is a computer tech says, it's an IBM. (“Idiot Behind Machine” problem) So to help the fellow masses with this frustrating scene, the following describes the proper way to care for and use a light microscope.

Handling and Care

Proper care for the microscope is necessary for full functionality. Carrying the microscope with two hands, one underneath the base and one hand grasping the arm, is important as not to drop or damage it. The electrical cord must stay neatly on the lab table. If it is allowed to dangle over the side of the table, it could be pulled off . Lens paper needs to be used when drying all slides to reduce chances of the slide being scratched.

Setting Up A Slide

When placing a slide on the stage of the microscope, make sure the sample is placed over the glass circle on the stage so that the light can shine through. Secure the slide with the mechanical clamps to keep the slide from moving awkwardly while adjusting the stage back and forth.

Oculars and Powers

View the slide on the lowest power (the shortest ocular on the nosepiece). From here, adjust the level of brightness of the light as needed. If greater definition of the object is desired, click a high power ocular into place. Make sure the new ocular is clicked fully in place or

else you will not see the slide properly. Caution needs to be exercised when changing the powers of the lenses. The high the power, the longer the ocular. If the stage is set really close to the low power, switching to a higher power without adjusting the stage properly can result in scratches or cracks to the slide. Using a higher power lens will require less light. Adjust the diaphragm to let in less light.

Viewing

The view through a microscope is like looking through a mirror. The view is backward in relation to the naked eye view. (Like the “e” lab) The “e” was turned 180 degrees when viewed through the microscope. This means that if an organism appears to be moving to the left when looking through a microscope, the organism is really moving to the right. The stage must be adjusted appropriately.

Focus

The coarse focus and the fine focus will move the stage up and down to allow for fine tuning a result. The danger in adjusting the coarse focus when using a high power is the same as adjusting the stage. If the lens gets too close to the slide, it could be damaged. Use the fine focus once the organism is seen.

Sometimes, the users eyelashes can be seen and get in the way of viewing the organism. In this case, moving the eye closer to the eye piece will usually solve this problem.

Use of Prescription Glasses or Contact Lenses

Glasses need not be worn while looking through a microscope. Glasses and contacts should be removed before using a microscope. It could cause the eyes to strain from over usage of increased magnification.

Did You Break It?

At $600-$800 each, microscopes are expensive toys that no one wants to be responsible for breaking. Following general best practices while using microscopes will help in finding the organism and it's organelles better and keep the microscope in good working order for the next student.