The Field Of Microbiology

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The field of Microbiology allows scientists to identify microscopic organisms and their importance in the world. The purpose of this paper is to present differential media as well as common experiments along with utilization of the microscope to identify the unknown organism 52. One of essential technique for the laboratory identification or the unknown organism is the use of aseptic technique. Aseptic technique allows the transfer of organisms from one medium to another without contamination of the culture as well as the surrounding environment (1). This is an essential technique to master because contamination of the initial culture medium or the subsequent media can alter results. In order to identify the unknown organism 52 inoculation …show more content…

Positive control organisms provide expected results for a known organism while the negative control organisms provide no results for the selected experiment. The following sections discuss different materials and methods used to isolate and identify the unknown organism 52. Section II – Material and Methods Unknown 52 was initially grown in a Tryptic Soy Agar (TSA) plate, which is an undefined medium where the exact composition of the nutrient was not known. TSA plate was incubated for 24 hours at 35 oC which showed isolated colonies that were small, white, flat smooth margins, round, shiny colonies on the medium (1). Microscopic Examination Unknown 52 was observed under oil immersion using the bright-field light microscope 1000x magnification after conducting Gram stain technique. Escherichia coli (Gram negative rods) pre-prepared slide was the negative control while the Staphylococcus epidermidis (Gram positive cocci) pre-prepared slide provided the positive control in order to deduce the results of unknown 52. Unknown 52 exhibited purple color cocci which was consistent with S. epidermidis organism. It can be concluded that unknown 52 was a Gram positive cocci. The purpose of Gram stain technique was to identify the present or absence of thick peptidoglycan layer outside the cell (1). Gram positive organisms contain a thick peptidoglycan layer while Gram negative organism contains a thin

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