The purpose of this lab is to isolate a bacterial population from the normal throat flora. A streak plate method will be used to obtain a pure culture of a Gram positive coccus genus of bacteria. Several biochemical tests will be performed to aid in the identification of this unknown bacterium. Biochemical tests are a series of tests used to identify certain bacterium The various tests that are used in this lab are the catalase test, oxidase test, blood hemolytic test, MSA, blood agar, and PEA/ab sens test. A known Gram positive coccus bacteria will be used alongside an isolated Gram positive unknown bacteria for comparison to aid in the ability to identify the isolated organism to the genus level.
There are many reasons for identifying an unknown bacterium. Some reasons to identify an unknown bacterium could help one determine if the unknown could cause illness in living things or help make antibiotics to kill bacteria that can cause some illnesses. Bacteria are necessary for the maintenance of human health. An important function of our normal flora is to protect us from highly pathogenic organisms. Some pathogenic bacteria also pose a major health threat by causing diseases.
Staining techniques are going to be performed in this lab to determine if the unknown bacteria is indeed Gram positive or Gram negative. The type of bacteria being investigated in this lab is Gram positive bacteria. Gram positive bacteria are those that are stained dark blue or violet by Gram staining. Gram positive organisms are able to retain the crystal violet stain because of the high amount of peptidoglycan in the cell wall. (Wikipedia). It is important to know whether the unknown bacteria is Gram positive or Gram negative because Gram positive bacteria can be killed with antibiotics. Doctors are also able to determine which type of antibiotic to use to kill the bacteria that can be causing a significant health threat in their patients. Not all Gram positive...
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