Environmental Microbiology Lab Report
Collection, Observation, and Analysis of Microorganisms in the human environment
Introduction
The necessity and value of collecting, identifying, and analyzing the various microbes regularly encountered in the daily human environment becomes quite apparent when one gains even a very basic knowledge of how diseases are acquired and spread. The purpose of this lab was to collect and observe microbes from environmental and human body samples by culturing them on the appropriate media using aseptic transfer techniques.
Materials • Distilled water • Test tube • 6 Unopened packages of 1 sterile cotton swab • 2 sterile nutrient agar Petri dishes • 1 sterile blood agar Petri dish • Incubator • Refrigerator • Bunsen burner • Gas connection • Plastic tubing • Inoculating loop • 12 sterile glass slides
• Wax pencil • Igniter • Crystal violet dye • Gram’s iodine • Ethyl alcohol • Safranin dye • Paper towels • Wire rack • Sink • Brightfield compound microscope • Lens paper • Immersion oil • Pen and paper
Methods
I. Collecting the environmental specimens:
1. Place some distilled water into the test tube.
2. Open one package of sterile cotton swabs by peeling apart the packaging at the top. Do not peel the package apart completely, just at the top.
3. Take out the cotton swab, dip it into the test tube of distilled water, and place it back into the original package with the cotton tip facing down.
4. Repeat the previous two steps for three more unopened packages of sterile cotton swabs.
5. Choose four locations from which environmental samples can be taken. (For example, use the bottom of a shoe, a light switch, or a
Introduction
The necessity and value of collecting, identifying, and analyzing the various microbes regularly encountered in the daily human environment becomes quite apparent when one gains even a very basic knowledge of how diseases are acquired and spread. The purpose of this lab was to collect and observe microbes from environmental and human body samples by culturing them on the appropriate media using aseptic transfer techniques.
Materials • Distilled water • Test tube • 6 Unopened packages of 1 sterile cotton swab • 2 sterile nutrient agar Petri dishes • 1 sterile blood agar Petri dish • Incubator • Refrigerator • Bunsen burner • Gas connection • Plastic tubing • Inoculating loop • 12 sterile glass slides
• Wax pencil • Igniter • Crystal violet dye • Gram’s iodine • Ethyl alcohol • Safranin dye • Paper towels • Wire rack • Sink • Brightfield compound microscope • Lens paper • Immersion oil • Pen and paper
Methods
I. Collecting the environmental specimens:
1. Place some distilled water into the test tube.
2. Open one package of sterile cotton swabs by peeling apart the packaging at the top. Do not peel the package apart completely, just at the top.
3. Take out the cotton swab, dip it into the test tube of distilled water, and place it back into the original package with the cotton tip facing down.
4. Repeat the previous two steps for three more unopened packages of sterile cotton swabs.
5. Choose four locations from which environmental samples can be taken. (For example, use the bottom of a shoe, a light switch, or a