Unknown Lab Report

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The focus of this lab was to identify an unknown organism based on its characteristics and the results from each of the tests. There will be various of test to choose from in order to identify the unknown organism, which will eliminate numerous possibilities and narrow it down to one. All the fundamental skills that we have learned and practiced in the lab will be used to perform on our unknown such as aseptic technique, microscopic examination, the use of differential media, and determining if it’s positive or negative. Performing aseptic techniques is the most crucial step that requires the utilizing of transferring, inoculating, and storing bacterial cultures and media. Aseptic technique is defined as procedures that prevent contamination …show more content…
Determining the cell shapes will help with the process of elimination organisms. Under microscopic examination for my unknown 16 broth, it appears to be a coccus shape and a gram positive. Gram staining can determine cell morphology, size, and arrangement. In a positive gram stain, a primary stain called crystal violet is used to stain the cell. For every new stain, mordant, decolorizing agent, and counterstain, it must be rinsed with distilled water. Then mordant is added, creating a crystal violet-iodine complex. The slide’s then rinsed with 95% ethanol until it turns clear and rinsed again with distilled water. A counterstain called safranin is used to stained the cell last. The method of gram staining will help determine whether the unknown is gram-negative or gram-positive. My unknown illustrates a purple colored stain in the microscope and it reveals a positively charged stain. Gram- positive has a thick peptidoglycan layer which traps the Crystal Violet so it doesn’t leak and this is why gram-positive bacteria looks purple under the …show more content…
Bacteria that produce catalase can be detected easily using typical store-grade hydrogen peroxide (Leboffe & Pierce, 2010). Bubbles start to form with the addition of 2 drops of hydrogen peroxide. This result concludes that unknown 16 is catalase-positive and it also produce the enzyme catalase. The unknown has the ability to live in the presence of oxygen and it was converted from hydrogen peroxide into gaseous oxygen and water. Micrococcus luteus was used as a positive control and Enterococcus faecalis was used as a negative

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