Gram Stain Lab Report

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Abstract This experiment was carried out to determine the species of the unknown organism. Once a choice of the unknown was made a Gram stain was conducted to determine the gram nature and morphology of the organism which was Gram negative bacilli. Based on those results a citrate utilization test was performed resulting in a positive test. Following the flow chart the next test to conduct was a motility test which also had a positive outcome. Lastly, a glucose fermentation test was conducted to determine the unknown organism. The glucose fermentation test yielded negative results indicating that the unknown was Pseudomonas aeruginosa. Introduction P. aeruginosa is a pathogen of plants and animals, it is free living that can be found in water…show more content…
The first of the four test was a Gram-stain. Once the experiment was completed the slide was then placed under a microscope where it was then categorized as Gram-negative bacilli. Its pink color when viewed through the microscope indicated that the test was Gram-negative and its rod shape indicated the morphology was bacilli. With these results the next test to be conducted was the citrate utilization test. A citrate tube was inoculated with P. aeruginosa and incubated at 37 degrees Celsius at 24 hours. Once the time elapsed the tube was viewed and it changed from its green color to a dark blue color indicating a positive test. Based on these results the next test administrated was the motility test. A inculcating needle containing P. aeruginosa was placed into the motility medium using aseptic technique. The tube was then placed into an incubator at 37 degrees Celsius for 24 hours. After 24 hours passed the test was examined and growth was seen radiating from the stab line which indicated a positive test. Lastly, a glucose fermentation test was conducted, P. aeruginosa was aseptically transferred into a tube of glucose broth using an inoculating loop. The tube was then placed into an incubator at 37 degrees Celsius for 48 hours. Once the time had elapsed the tube appeared pink which indicated a negative test. With the negative result the unknown species was identified as P.
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