Gram Stain Lab Report

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To limit the amount of errors or contamination in any procedure lab safety rules, gloves, and the aseptic technique was strictly enforced throughout the experiment. The first step to identifying the unknown bacterium was the Streak Plate Method. This method is used to isolate a pure culture from a mixed culture. Also, this method included streaking a tryptic soy agar (TSA) plate into four quadrants, and later incubating the plate for 24 hours. The second step performed was the Gram Stain test. The Gram Stain was used to determine whether the unknown bacterium was gram-positive or gram-negative. First, the unknown sample was smeared onto a slide along with a drop of distilled water. Second, the unknown was air dried and was heat fixed. Third, a series of stains/solution such as crystal violet, iodine, ethanol, and Safranin were used to complete the Gram Stain. During this process each stain/solution was left on the emulsion for a limited amount of time. Also between each stain, there was a removal of the previous stain by rinsing the slide clear with distilled water. After the gram stain was completed, the slide was blotted dry with bibulous paper and was placed under the microscope. While under the microscope, a drop of oil …show more content…

The Catalase test was used to determine whether or not the unknown contains Catalase enzymes that would react when hydrogen peroxide was added. If the unknown contained Catalase enzymes then the unknown would bubble/fizz when the hydrogen peroxide was added, and would be recorded as a positive reaction. If the unknown did not contain Catalase enzymes there would be no reaction, and would be recorded as a negative reaction. The procedures for this test included: obtaining a microscope slide with your unknown sample on it and placing 1-2 drops of hydrogen peroxide on it. The results of the Catalase test would be determined that same

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