Ramses Meza BIOL 1408 Lab 5. Microscopy

Objectives:  Identify when a stereomicroscope (dissecting microscope) versus a compound light microscope would be used in the lab  Describe the major differences between light microscopes and electron microscopes  Identify the parts of a compound light microscope and stereomicroscope  Describe the proper way to carry a microscope  Determine the total magnification of an object being viewed by a compound light microscope if given the ocular lens and objective lens magnifications  To prepare wet mounts of animal and plant tissues Vocabulary:  Microscope  Compound light microscope  Stereomicroscope Introduction: Many organisms (bacteria) and parts of organisms (cells) that biologist's study are too small to be seen with the human eye. We use microscopes (micro- = “small”; -scope = “to look at”) to enlarge specimens for our investigation. The word microscope means “to see small” and the first primitive microscope was created in 1595. Figure 1 shows us the sizes of various objects and illustrates which microscope would be most appropriate to use when viewing them. Ramses Meza BIOL 1408 Figure 1: Illustration of the sizes of various objects. Credit: Jeremy Seto and derived from works by IgniX, Gringer, Jiver, Ninjatacoshell, Ali Zifan (CC-BYSA) There are several types of microscopes, but you will be mostly using a compound light microscope. This type of microscope uses visible light focused through two lenses, the ocular and the objective, to view a small specimen. Only cells that are thin enough for light to pass through will be visible with a light microscope in a two-dimensional image. Another microscope that you will use in lab is a stereomicrosc