Lab 2 – The Dissecting Microscope

Objective: allow student to become familiar with the dissecting microscope [also called the stereoscopic microscope].

The dissecting microscope is very different from the compound/light microscope.Light is not transmitted through the sample; instead, light is bounced off the sample, passes into an objective lens, and then through a pair of ocular lenses to your eyes.Dissecting microscopes are useful for examining objects too large to view with a compound microscope, and for low-power magnification.They allow examination of the surface structure of 3-D objects.

Procedure:

1. Get a dissecting scope. Take a few minutes to familiarize yourself with it, notice it is a bit different from the compound microscopes in its complexity. Turn on the light for opaque viewing.
2. Place a coin on the stage, and examine it with both objectives to accommodate for differences in acuity in your eyes, focus first with the focusing knob while viewing through the ocular that cannot be individually adjusted. Then using the focusing ring on the other ocular to bring the object into sharp focus for that eye. Practice focusing until you are good at it. Move the coin on the stage, noting the direction in which the image moves when the coin is moved. 
3. Look at different coins; observe them at high and low powers. What if anything is remarkable about them?
4. Place a few hairs of various colors/textures on the stage. Observe them with both objectives. Compare their appearance to the compound microscope. Sketch the hairs, note what power the sketch is from. 

5.Place your fingertips, nails down, at the center of the stage.Focus on the ridges and grooves that produce your unique fingerprint.Sketch your fingerprint, and note the magnification.