Then a nitrite test was performed and nitrate reduced to nitrite having a positive reaction and eliminating Enterococcus faecalis. Through this experiment, gram staining skills develop. Materials and Methods Please refer to packet for materials and methods listed under 1. The unknown gram negative bacteria had a negative reaction verifying that the unknown bacteria is Escherichia coli. Each test performed, provided us with some key information about the unknown microbes in question and how the bacteria function. Answer: Petri plates containing solid media provides a large surface area for streaking bacterium and the observation of bacterial colonies.
A positive urea test eliminates Staphylococcus aureus which leaves Staphylococcus epidermidis. The results of the exercise or experiment are what are being showcased, not the writing. Objectives Aim of this experiment is to differentiate between the two major categories of bacteria , gram positive and gram negative. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. The specific Gram Negative Enteric Bacilli was Shigella dysenteriae.
Then we add 50 ml of distilled water to each substance, sodium carbonate dissolved faster than calcium carbonate. If the slide is not heated enough, all of the bacteria will wash off. Two or more loopfuls of liquid media containing the organism can be placed on the slide. The next step was to use 95% Ethanol to w ash off the dyes from the G ram-negati ve bacteria. It stains only the background providing greater contrast. Gram staining bacteria requires the use of aseptic technique to ensure the sterility of the experiment.
Since virtually every living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquatic life. Staining is a process in which microbes are stained to enhance contrast in the microscopic image. If too much culture is added to the water, you will not see stained individual bacteria and you may not have a reliable Gram stain. Then was waited for air drying. Introduction: The purpose of this lab was to determine the identity of an unknown bacteria slant culture using a series of differential tests.
The citrate test showed a negative result with no color change or growth of the unknown bacterium. Kevina Smith Lab 1: Microscopy and the Metric System Part A: Microscopy Purpose The purpose of this experiment was to learn how to use a microscope correctly and perform wet mount slides accurately, thus becoming more familiar with the microscope. We embarked on the project with the knowledge that we would have to identify a Gram + as well as a Gram - from the species that were given and the experiment proceeded as follows. Procedure Two - Culturing Bacteria Using Aseptic Techniques 1. Other use is for throat lozenges because of its anesthetic effect.
Acid production did occur meaning carbohydrates were fermented and eliminating Proteus vulgaris. The outer membrane of the Gram-negative cell is lost from the cell, leaving the peptidoglycan layer exposed. With the knowledge gained from the sessions in the laboratory, we can now. Mannitol test detects the carbohydrate fermentation which leads to acid production. The Voges-Proskauer test came back with a negative result. Because of the large size of amylose and amylopectin molecules, these organisms cannot pass through the bacterial cell wall. Stain with Gram's iodine solution for one minute and gently wash with water.
Cereus and determined which were gram positive or gram negative. The gram positive bacteria did produce urease having a positive reaction, eliminating Staphylococcus aureus and leaving Staphylococcus epidermidis. In Gram staining process, firstly the ready smear was placed to staining pool. Some of these techniques were simple staining, gram staining, and isolation techniques. The unknown broth contains a gram negative bacterium and a gram positive bacterium.
Provide a reason for the differences in total bacteria in theses two places. We did so to determine how many and what kind of bacteria could be found there. Magnification is the enlargement of a specimen while resolution is the ability to distinguish detail or the ability to distinguish between distinct points. To receive full credit for Exercise 8, you must submit the following: 1 The typed Exercise 8 report form, complete with all of your data recorded and questions answered. Materials and Methods The materials used for this lab were stock solution, agars, slant agars, Bunsen burner, loop, microscope, slide, and stains. Biochemical tests were started and incubated, after the T-streak results showed no contamination or mixture of organisms, for 24 hours in a hot room of 37 degrees celcius.