Kristina Simonovic Section O 10 Feb 2016 Exercise Four Title Sterile Technique Quiz Dental Plaque Gram Stain Gram Stain Unknown Quiz Hypothesis If the culture tubes are sterilized properly then the culture will remain sterile when incubated If the specimen is gram stained then it will be clearly viewed under the microscope Methods Aseptic Technique Quiz Transfer sterile trypticase soy broth from the culture bottle to sterile tubes aseptically Transfer 0 5mL to tube 1 Transfer 4 5ML to tube 2 and 5 0mL to tube 3 Transfer 9 5mL to tube 4 Transfer 9 0mL to tube 5 Transfer 10 0mL to tube 6 Now transfer 0 5mL from tube 3 to tube 2 Transfer 0 5mL from tube 3 to tube 1 Transfer 0 5mL from tube 3 to tube 4 Transfer 1 0mL from tube 4 to tube 5 Dental Plaque Gram Stain Prepare a wet mount of your oral microflora Put a drop of water on the slide and then using a toothpick scrape under the gum line and mix the material from the toothpick into the water on the slide Cover the slide with a coverslip and view it under the phase contrast microscope Then perform a gram stain on the organisms from your dental plaque and view it under the microscope a second time Gram Stain Unknown Quiz Put Bacillus megaterium Escherichia coli and Staphylococcus epidermidis on one slide Heat fix the slide and then stain it with Crystal Violet for 2 minutes Rinse the slide with distilled water and then stain it with Gram s Iodine for another 2 minutes Rinse the slide with 70 ethanol and then again with distilled water and then stain it with Safranin for 6 minutes Rinse the slide with distilled water blot dry it and then view it under the microscope Identify the three organisms Safety Concerns 1 Wear safety goggles while working with stains 2 Do not get oil on the 10 and 40 power lenses 3 Flame sterilize the culture tubes and dispose of the pipettes after each transfer Relevance Learning how to properly perform the aseptic technique and the gram stain is a fundamental part of microbiology