The microscope is perhaps the most common equipment in any microbiology lab, since it enables students and professionals to examine organisms and structures invisibles to the naked eye. There are microscopes with several different magnification levels, ranging from hundreds to thousands of hundreds in diameter. Of course, the price of a microscope increases with its quality, but even the simplest microscope can provide amazing views of the microbiology world.


Each kind of microscope and each technique of material preparation offers some specific advantages on the demonstration of certain morphological elements. In this article series, we will learn the principles and types of microscopes, as well as some of the microbiological methods used to observe the dimensions, the shapes and structural characteristics of microorganisms.

The microscopes fit into two categories: light (or optical) and electronic, depending on the principle or method of magnification employed. In light microscopy, the magnification is obtained through a system of optical lenses while in electronic microscopy a bean of electrons is used to produce the enlarged image.

The light microscopy can be divided into six sub-categories: bright field microscopy, dark field optics, ultraviolet microscopy, fluorescence microscopy, phase contrast microscopy and differential interference contrast (D.I.C). Beginners will much probably use bright field microscopy to examine their samples, since it is by far the most common technique employed in research and quality control labs. However, it is very important to know the other applications, for each one has a unique property that makes it especially desirable for the demonstration of specific morphological structures.

See you tomorrow for the next lesson: parts and functions of a light microscope.