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Local Alignment Search Tool

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Basic Local Alignment Search Tool (BLAST)
The Basic Local Alignment Search Tool (BLAST) was the final portion of this lab report. BLAST is provided courtesy of the National Center for Biotechnology Information (NCBI). After running the five chosen tests, students were given the two 16S rRNA sequences that were associated with their assigned culture. The BLAST results served to confirm or disprove the hypothesis of what the unknown may be. The BLAST program compared the given 16S rRNA sequence to a database of known sequences and searched for similarity. (10) This search tool is capable of comparing nucleotide or protein sequences to find statistical significance between the matches. A perfect match to the unknown sequence is indicated by a …show more content…

There were two different types of colony forming units present on the TSA plate after incubation. The one chosen to be used for identification of unknown 28 was the larger of the two colonies. The chosen colony was roughly 1mm in diameter and were round in shape. The color was white and slightly waxy. The colonies were convex in elevation and had smooth margins. When compared to the controls in the laboratory, the unknown colony was considerably smaller in size. The Staphylococcus epidermidis control colonies were larger in size and lacked round margins . Although the color between the control and unknown was similar, S. epidermidis had colonies with irregular margins and plateau …show more content…

After appropriate incubation, sulfanilic acid (reagent A) and dimethyl-α-napthylamine (reagent B) were both added to the test tube. A color change should have been observed after approximately one minute if the unknown was positive for nitrate reduction (1). However, no color change was present which indicated no nitrate reduction. As a confirmation test, powdered zin was added to the tube. There was an immediate color change to red after the addition of zinc. The color change from zinc indicated that there were still intact nitrates within the broth, thus, no reduction had occurred. The positive control for nitrate reduction was E. coli which changed to a red color after the addition of reagents A and B. The negative control was M. luteus which had

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