Aseptic Technique and Transfer of Microorganisms

2389 WordsJul 10, 201210 Pages
Introduction: Microbes, also called microorganisms, are minutes living things that individually are usually too small to be seen with the unaided eye. The group includes bacteria, fungi (yeast and molds), protozoa and microscopic algae. It also includes viruses, those noncellular entities sometimes regarded as straddling the border between life and nonlife. People tend to related these microbes only with major disease such as AIDS, uncomfortable infections, or such common inconveniences as spoiled food. However, the majority of the microbes play important role by helping to maintain the balance of living organisms and chemicals in our environment. Though only a minority of microbes are pathogenic (disease-producing), practical knowledge…show more content…
Usually, to obtain useful plates with most samples, the loop-dilution procedure will be conducted when doing pour plate method. This procedure is based on a roughly quantitative dilution of the original sample in agar medium. Procedures: A. Broth Culture Four tubes of nutrient broth were treated. 1. One tube was labeled as “Control” and was left uninoculated. The cap or plug was not removed. 2. The cap or plug was removed from one tube and a small amount of dirt or other foreign material was added into the tube. The plug is being replaced. 3. After the wire loop and the third tube of broth were flamed, the tube was inoculated with the pure culture of Escherichia coli. This procedure was repeated by inoculated the fourth tube with Micrococcus luteus. 4. The four tubes were incubated at room temperature for 2 days. B. Agar Slope(Slant) 1. Three tubes of nutrients agar were molten in boiling water. They were then cooled in an inclined position. 2. When the medium was cold and solid, one surface was inoculated with Escherichia coli by using a needle. The needle was moved gently on the agar surface from the bottom to the top; take care not to gouge the agar. The surface of the second tube was inoculated with Micrococcus luteus. The third tube was left uninoculated as the control tube. 3. Both culture tubes were incubated at room temperature for 2 days. C. Pure Culture Technique I. Streak Plate 1. Two
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