The Laboratory Without Contamination Is Essential For The Study And Classifications Of The Unknown Bacterial Culture

1203 Words Nov 12th, 2014 5 Pages
Introduction The ability to cultivate and identify organisms of interest in the laboratory without contamination is essential for the study and classifications of many life forms. Different techniques were used to differentiate the organisms. This process of transferring a microbe from one medium to the next is called inoculating. The organism chosen in class will be used to construct further testing. The purpose of this lab experiment was to find the identity of the unknown bacterial culture and use all the methods and the assessments that were introduced in the class. By doing that we had to use different techniques that guide us to find the right bacterium. A flowchart was given for the unknown to help us find the right bacterium that …show more content…
A large inoculate of the organism was placed in the center of a slide and a drop of KOH in a corner. The two were carefully mixed together by dragging the KOH into the organism. This step was done to determine whether the test was gram-positive or gram-negative. KOH lyses the gram negative cells and results in a sticky and stringy substance while the gram- positive remain watery in appearance. Once the KOH test was complete the SIM medium test was conducted, this test was done to determine three separate tests in one test tube. We are looking for the sulfur reduction, indole production, and motility of the organism. First, a SIM media tube is prepared, and then label the SIM tube with your initials and the bacteria you’re using. Next, use a needle to pick an isolated colony from the plate. Then, inoculate the tube by making a single straight stab down the middle of the tube to the bottom. Incubate the bacteria at 35-37 C for about 24 hours. After incubation examine the tube for sulfide, indole and motility. After that I added 2-5 drops of Kovac’s reagent and observed for a red layer. If a red layer appears then it is positive. Next I referred to my chart and it shows that I have to perform a Urease test. The purpose for this test was to identify the presence or absence of enzyme urease. First obtain a urea broth tube, inoculating loop, and label the tube with your organism name. Then use your inoculating loop to aseptically transfer the bacterium to
Open Document