Section I – Introduction: The purpose of this paper is to identify an unknown bacterium by conducting five tests and removing possibilities from the list of unknown genera. After explaining what the tests are for, and why they’re conducted. I then interpreted, analyzed, and explained the outcomes of each test. I was then given a 16S rRNA sequence that I’m able to input into the Basic Local Alignment Search Tool and find out what genus my bacterium is. Finally, comparing whether my results correlate with the bacterium shown after the Basic Local Alignment Search Tool. While conducting each research test, it has to be done using an aseptic technique. Aseptic technique is a way to prevent contamination of a sample. Contamination can be …show more content…
The ways we can examine organism is by using a microscope. We’ve used a bright-Field microscopy that shines light through a specimen (1). The organism is then magnified as light refracts through the four objective lens 4X, 10X, 40X, and 100X found on the revolving nosepiece. It is then further magnified as we look through the ocular lens at 10X. By multiplying the objective lenses and the ocular lens gives a total magnification of 40X, 100X, 400X and 1000X. Once reaching objective lens 100X oil needs to be put on the slide. By using oil, it increases the lens magnification because oil refracts light just like the lens in the microscope and it has the same refractive index (1). While completing the 5 tests I used medium that have a purpose selective and differential. Selective mediums “inhibit the growth of some organisms and encourage the growth of others” (1). Differential mediums differentiate between microorganisms using indicators such as color as the pH of the medium changes (1). I performed a gram stain on my unknown 7. It appeared to be purple and round shaped. I came to the conclusion that my bacterium is gram-positive, cocci. A gram stain is a differential test. It allows recognizing the difference between two cell walls structures. In a gram-positive cell wall contains a thick peptidoglycan layer covering the plasma membrane (2). The purple staining is retained around the cell
There are many reasons for identifying an unknown bacterium. 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. The experiment was done by applying methods in order to identify an unknown bacterium.
The purpose of this lab was to identify two unknown bacteria from a mixed culture. The reason for identification of unknown bacteria was to help students recognize different bacteria through different biochemical tests and characteristics. This is important in the medical field because identification of unknown bacteria can help treat a patient by knowing the contributing source of a disease. Also knowledge of different bacteria helped others make antibiotics used today. This lab was completed by using the methods learned thus far in identification of bacteria.
To perform this test, a small drop of water is placed on a clean microscope slide. A metal loop that has been properly sterilized in the blue flame and allowed time to cool is used to
Purpose: The purpose of this lab is to help you become a little familiar with some of the tests that can be typically performed in a clinical or research lab facility. These tests may help in determining a particular pathogen’s growth needs.
Today in medicine doctors are rapidly isolating and distinguishing the many pathogenic microbes encountered daily within the environment. Public health has been affected from the faster identification of microorganisms by delivering an accurate analysis to patients in order to receive treatment of the disease in a timely manner. Due to the growing understanding of these organisms more have been easier to indicate to improve water quality. Also more methods have been developed for better treatment options from fecal bacteria in public water systems. Scientist has developed such specific methods of identifying the unknown organism to tell if the contamination has come from either a human, bird, or mammal. (Achtman et al., 2008)
The first step toward identifying this unknown organism was to perform a Gram Stain to differentiate between gram positive and gram negative bacteria. This is an important step because it directs what the next tests will be. My Gram Stain on sample #12 showed that the bacteria was gram negative, however, after receiving the results of the OF glucose, H2S, Citrate, Urease and Motility tests, it was apparent that my Gram Stain was contaminated. I then performed a catalase test which came back negative, so I ordered a Bacitracin disc, Optochin disc and a CAMP test which had to be incubated overnight. After receipt of those test results,
The main idea of this experiment was to correctly identify the unknown bacteria, #3. Identification of unknown bacteria yields multiple benefits in many different areas in the research of microorganisms. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. Observations made from the tests were then compared to a gram negative unknown chart in order to identify the bacteria. Based off of my results and the chart, I concluded the bacteria #3 was the bacteria Escherichia coli. E. coli is most commonly found in the intestines of warm blooded organisms. Most E. coli strands are non pathogenic however, there are strands
My unknown organism #11 is Escherichia coli (E. coli). E. coli belongs to the family Enterobacteriaceae. E. coli is Gram-negative, facultative anaerobe, and rod-shaped bacteria (bacillus). [1]
This experiment was given to us to utilized previous knowledge learned throughout the semester to identify a gram negative unknown bacterium. We had to first learn the difference between a gram negative and a gram positive organism. We started off with doing gram stains to determine whether it was positive or negative. Based on the gram stains, a gram positive stains purple and a gram negative stains pink. A gram positive stains purple because the cell walls is made of a thick peptidoglycan layer and doesn’t
PCR is the amplification of DNA by denaturing, annealing, and extension of a DNA template. Specific sequences can be amplified using single-stranded DNA that complements the target sequences known as primers. This process heats DNA until the strands separate, then primers bind to the target regions. DNA polymerase enzymes and single base nucleotides (dNTPs) are used to synthesize new strands of DNA to the target sequence. The end product will contain large quantities of the target sequence (Bean et al. 2015). The most notable in phylogenic studies is the 16S rRNA gene, because of it’s highly conserved primer-binding site and hyper variable regions that provide species-specific sequences within bacteria and archaea (Kolbert and Persin 1999). This gene is a component of the 30S small subunit of prokaryotic ribosome’s and serves as the primary site of protein synthesis. (Woese and Fox 1977). The 16S rRNA sequence can be amplified and matched to national databases provided by the National Center for Biotechnology Information (NCBI) using software termed Basic Local Alignment Search Tool (BLAST) to find regions of similarity between biological sequences for bacterial identification. Thus, providing a cost effective and timely method when compared to biochemical
Gram staining is a technique used to determine if the bacteria is Gram positive or Gram- negative. Gram staining procedure uses crystal violet stain, iodine moderator, alcohol decolorizer and safarin counter stain. In Gram- negative bacteria the primary stain will be washed out with the decolorizer and it will be stained with the counterstain. Whereas in Gram-positive bacteria the primary stain will not leave the cell wall. This difference comes from difference in the structure of the cell wall that retains the stain.
The purpose of the bacterial unknown independent study experiment completed throughout the course of this lab was to determine the identity of an unknown bacterial species. The unknown bacteria sample was chosen from numerous samples provided by the instructor. The starting unknown sample, unknown #15 was a mixed bacterial culture and a broad approach taken to identify the sample. Various biochemical tests were completed to identify the bacterial species along with the use of databases such as Gideon and Bergey’s to compare the test results of known bacteria to the results of the unknown sample. Information was gathered from the other sources and databases and phenotypic testing completed and the results compared to the database results. Aseptic
Identifying microorganisms can provide information on diagnosing diseases and discovering the most beneficial treatment possible. The purpose of this assignment was to identify an unknown microorganism using biochemical tests and various methods that were practiced in the microbiology laboratory. In this paper, I will discuss the processes of how I came to identify my unknown microorganism.
A gram stain is performed to identify bacteria as gram positive or negative, and to visualize cell arrangement
Each medium has its own function (i.e.: Nutritional, selective growth, pH determining etc.) and these are used to determine the characteristics of organisms.