Tools Used in Microbiology

Microscopes

• The microscope is the fundamental tool of microbiology. A typical compound (multilens) microscope will have four sets of lenses, called objectives, on a revolving stand: scanning (4X), low power (10X), high dry (40X) and oil immersion (100X). They combine with the oracular lens in the eyepiece, which magnifies 10X by itself, so that even on a low scanning setting you get a magnification of 400X. The tiniest organisms require immersion oil to be seen properly; it refracts the light in a way that lets the microscope focus better.

Flasks, Test Tubes and Jars

• Flasks are used to store chemicals or cultures. Flasks come in various shapes -- some with caps and some designed to create suction. Test tubes hold cultures. A test tube with a cap on it can prevent outside air or bacteria from contaminating the culture. Jars hold laboratory supplies, such as the dye used to stain slides with, or candles, which can be burned in order to reduce the oxygen in the air, thus creating a more-favorable environment for some cultures.

Miscellaneous Small Equipment

• A pipette is a narrow tube used to measure and transfer liquid. Petri dishes are used to grow bacteria and fungi. Beakers are for boiling water and measuring liquids. Various other cylinders, tubes and bottles are used to measure, store, dilute and filter liquids of various sorts. Microbiologists also use safety glasses and special papers for cleaning various instruments. Inoculating loops and wires, hand tools with small wires on the end, are for transferring microbes.

Miscellaneous Large Equipment

• A spectrophotometer measures microbial growth and other things using light intensity. A centrifuge breaks cells down to release their constituent parts. Heating devices include a hot air oven, for dry sterilization; an autoclave, for steam sterilization; and an incubator, for encouraging microbial culture growth. Microbiologists use a pH meter to measure the pH -- acidity -- of liquids and a balance to weigh substances.