How to Use a Polarized Light Microscope

The magnification lenses on a microscope rotate easily.

Polarized light travels on one plane or, very simply, in one direction, according to Physics Classroom. Unpolarized light, on the other hand, travels in a multitude of directions. Forms of this light include the light from the sun, or from a lamp. A microscope using polarized light allows you to see an object by reflecting light onto or through the object placed in the microscope. Once you learn the basics of polarized light microscopy, using a polarized light microscope is rather easy.

Things You'll Need

• Prepared slide

Instructions

1. Place your prepared slide on the square or round microscope stage, with the center of the object you want to view placed in the center (usually a transparent area in the stage).

2. Turn the microscope to "low power." On a microscope, low power equals the lowest level of magnification. Microscopes indicate levels of magnification with numbers preceding an "x," so the lowest number preceding an "x" indicates the lowest power or magnification.

3. Lower the lowest magnification lens all the way, without touching the slide, using the "coarse focus" knob. Out of the two focusing knobs on a polarized light microscope, the "coarse focus" knob often appears larger than the "fine focus" knob. Look through the eyepiece.

4. Turn the "coarse focus" knob slowly, raising the magnification lens until the object in the slide focuses.

5. Turn the "fine focus" knob if the "coarse focus" knob did not focus in on your slide.

6. Change to the larger magnification by gently rotating the objective lenses. When focusing the microscope on high magnifications, only use the "fine focus" knob.

Tips & Warnings

• Some microscopes also contain a red lens. Do not use the red lens without the aid of an instructor, as the lens requires oil lubrication. Without lubrication, the red lens can break.

References

• Staples High School: How to Use a Microscope
• Physics Classroom: Polarization