BIOL240 Study Guide - Quiz Guide: Lactobacillus Plantarum, Serial Dilution, Potassium Alum
Document Summary
Experiment 11: streak-plate method isolation of pure culture. Pure culture: culture consisting of only type of microorganism. 3 dilution methods commonly used for the isolation of bacteria: streak plate essential dilution technique that spreads a loopful of culture over the surface of an agar plate, spread plate, pour plate. Dilute the specimen into a series of cooled (45-50 degree) fluid-agar medium which is then poured into empty petri plates. It is necessary to make several dilutions to ensure that at least one countable plate will be obtained on which distinct and separate colonies have formed on, or in, the agar medium. Used mixed cuture of escherichia coli and staphylococcus aureus. Practice in handling pipettes in an aseptic manner. Sterile technique will be measured by the absence or presence of bacterial growth in nutrient broth. Pipettes are frequently used to transfer bacterial suspensions or to create serial dilutions.