We got this because we forgot to weigh the evaporating dish at the beginning of the experiment and then again when it had the solution in it. Not all of the tests were performed on every culture, however, as some of the tests were used only for gram + or gram — bacteria, while others were even more specific and used only for cocci bacteria. Catalase is tested for by adding hydrogen peroxide to the culture, and looking for the production of gas bubbles. The chemical formula of a hydrate can be determined by analyzing the percent water in the hydrate, the ratio of the mass of water lost upon heating divided by the mass of the original hydrate. It can cause many illnesses, from minor skin infections, to life threatening diseases such as meningitis, pneumonia, osteomyelitis, endocarditis, toxic shock syndrome, and sepsis Todar, 2012. There easily could have been some left and this accounts for the small difference in results between the two methods.
Lab Manual for General Microbiology. Motility is if a bacteria is mobile or immobile. Water vapor becomes very obvious and starts to gather on cover. The first method used will be the Fajan titrimetric method which uses an adsorption indicator. The purpose of this study was to identify a Gram positive and a Gram-negative bacterium from a mixed culture.
What does the blood agar select for? The flow charts on the following page list these tests and results for the Gram positive and Gram negative bacteria. This condition can exhibit lethargy, vomiting and not being able to breathe. The goal of this lab report is 1 to demonstrate comprehension of the methods and lab techniques learned during the semester 2 to explain the tests performed on each isolated unknown that led to the identification of each unknown 3 and to give a background on the characteristics, pathogenicity and some uses of one of the identified unknowns. Place the glass cover on the container and heat the container for 4-8 minutes the container should be about 5. S aureus can become pathogenic through tissue invasion and toxin pollution. Staphylococcus aureus is in the Staphylococcaceae family.
The writing of laboratory reports is an essential part of any practical module in Psychology. Materials and Methods The professor gave out the unknown specimens. Potassium chloride has around 47% chloride in it. The tests were performed in such a way that each test eliminated a possible unknown candidate. To each sample add 5 drops of dichlorofluorescein and about 0. Gram stains were performed on each culture.
It was only let to incubate for 24 hours at 37 degrees Celsius instead of 48 hours. The only slight issue was that B. This results in complete clearing of the blood around the colonies. The setup could have been more effective if we read the directions before we started the experiment and highlighted the important parts of the experimental procedure. Habituation of Exploratory Behavior in Rats Regarding Spatial Rearrangement of Familiar Objects in an Open Field Habituation of Exploratory Behavior in Rats Regarding Spatial Rearrangement of Familiar Objects in an Open Field Habituation is Although it might seem obvious that rats would habituate to an unfamiliar environment after repeated exposure, it is not as obvious how behavior would change as a result of new stimuli within that familiar environment. Discuss the validity and reliability of your data in answering the question. The tests performed and what constitutes a positive and negative test are as follows.
To do this, you will need to heat the hydrate with a flame in order to evaporate the water see Figure 1. Your report should answer these questions in 2 pages or less. This study was done by applying all of the methods that have been learned so far in the microbiology laboratory class for the identification of an unknown bacterium. Firstly, each of the tests in the series ruled out a possible candidate until P. The identification of these unknown cultures was accomplished by separating and differentiating possible bacteria based on specific biochemical characteristics.
Very carefully pour out 4-5 mL of the solution into the evaporating dish. It is a good way to see which method is more accurate and which method is more practical. Continue to titrate drop by drop while swirling until the precipitate turns pink. The first procedure performed was an isolation of the unknown bacteria with the goal of obtaining a pure culture. Furthermore, some probiotic companies are using B. The reasons range from medical purposes, such as determining if the unknown could cause ailments in living things or knowing what microorganisms are needed to make antibiotics to other purposes such as knowing the exact microorganism has to be used to make certain foods.
Put the thermometer in the solution in the flask and softly stir the flask. In this method, an adsorption indicator is used such as dichlorofluorescein. Techniques such as the quadrant streak and proper use of an inoculating loop learned in class were used in this study. Introduction: The purpose of this lab was to determine the identity of an unknown bacteria slant culture using a series of differential tests. Environmental and Industrial Use of Bacillus Subtilis.
Using the hot water bath, carefully evaporate the solution. The first is to identify the compound by identifying it's physical and chemical properties. Filter each sample that was just titrated using gravity filtration. There is not a significant difference between methods. Mix thoroughly and transfer to a brown bottle to ensure the solution does not react with the light. Adjust the Bunsen burner so that it produces a flame with a blue oxidizing cone about 2-3 cm above its top. Alpha hemolysis refers to the partial lysis of red blood cells and hemoglobin.