Preview

One Another by Their Morphology

Good Essays
Open Document
Open Document
533 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
One Another by Their Morphology
Bacteria can be distinguished from one another by their morphology (size, shape, and staining characteristics). In this lab experiment, bacterial morphology was examined by observing both stained and unstained organisms.
A wet mount is a preparation process where a live specimen in culture fluid is placed on a slide and the organism is free to move about. In the wet mount slides provided via LabPaq software with cheek, dental plaque, and yeast specimens were observed. The wet mount preparations were difficult to observe because of poor contrast, however, a common occurrence in the specimens were cells large in size and translucent in color. The slides provided with direct staining using crystal violet gave the most imagining of morphology. The directly stained cells gave off a purplish hue to the cells, making them easier to visualize and classify. The indirect specimens stained with congo red provided translucent cells while others were a brownish red, however, the cellular characteristics were easily distinguishable. There was no experiment provided in which indirect staining using both congo red and crystal violet was undertaken. It may be hypothesized therefore that in this case one may observe both red and purple stains of cells depending upon the negative or positive component of the cell.
Staining enhances the visualization of smears and reveals differential characteristics such as morphology. As stated previously, utilizing a wet mount prepared slide, the specimens were difficult to visualize. However, using the staining methods, specific bacterial morphologies were identified. For example, at 100x, a direct stain of yeast returned a cluster of cocci.
A stain is a chemical that adheres to structures of the microorganism and in effect dyes the microorganism so the microorganism can be easily seen under a microscope. Stains used in microbiology are either basic (direct) or acidic (indirect). Basic dyes are used for positive or direct staining

You May Also Find These Documents Helpful

  • Good Essays

    A wet mount stain is when a drop of water is placed onto the microscope slide. The water on the slide helps to support the organism and sample. The water fills the space between the cover slip and the slide. This action allows the light from the microscope to pass through the slide and the sample for better visualization of the organisms. A direct stain occurs when a charged color portion of a basic dye like methylene blue combines with the negatively charged portion of and organism allowing the bacterium to become directly stained. In direct staining, the organisms must be fixed by a process such as heat. Fixing the slide prevents the organism form washing off the slide before visualization. This is accomplished by passing a smear of the bacteria through flame. The heat sets the proteins of the organism thus causing the bacteria to attach to the slide. The organism can become damaged from the setting process and the use of heat prior to staining. In indirect staining, the negatively charged colored portion of an acidic dye is repelled by the negatively charged bacterial cell wall. This causes the background to be stained while leaving the organism’s cell wall to remain colorless and unstained.…

    • 588 Words
    • 2 Pages
    Good Essays
  • Good Essays

    C: When we are talking about difference between direct and indirect stains, main importance is acidity of the dye. Dye that we are using in direct staining is basic. The colored part of this dye is positive charge, but when in contact with negative cytoplasm of bacteria, at that point bacteria change color and become stained with purple hue. For direct staining we are using crystal violet or methylene blue stain. For indirect staining we are using dyes that are acidic. Usually we are using Congo red, nigrosine or India ink. The acidic dye contains negatively charged color portion. When applied and in contact with…

    • 472 Words
    • 2 Pages
    Good Essays
  • Powerful Essays

    From the streak plate, several slides were made to determine the morphology of unknown 45. A Gram stain, used to indicate the type of cell wall possessed by the bacterium, was performed. U45 stained a bright pink color and were small ovals and rods in shape. This indicated that U45 was a gram-negative bacillus bacterium. A capsular stain was then performed to determine the presence or absence of a capsule. Unknown 45 was positive for capsules. Having determined that U45 was gram-negative, there was no need to perform the Schaeffer-Fulton endospore stain, which is used detect the presence of endospores in certain gram-positive bacteria.…

    • 1738 Words
    • 7 Pages
    Powerful Essays
  • Powerful Essays

    Unknown report Micro

    • 1261 Words
    • 5 Pages

    Gram staining, the most commonly used differential stain, allows for the fast and easy detection between gram negative and gram positive organisms based on the presence or absence of peptidoglycan. A gram positive organism resists the decolorization process due to a large amount of peptidoglycan and appears a purple color. A gram negative organism is successfully destained, counterstained with safranin and appears reddish-pink.…

    • 1261 Words
    • 5 Pages
    Powerful Essays
  • Good Essays

    Chains of both cocci and bracillus cells were both visible and identifiable. The chains varied in length. The cheek and yeast smear was clearer. The same shapes were seen as before just with sharper outlines. The cells were much easier to see with more detail.…

    • 391 Words
    • 2 Pages
    Good Essays
  • Better Essays

    Micro lab quiz 2

    • 1967 Words
    • 8 Pages

    Simple dyes used to stain bacteria have a positive charge cationic (+), therefore, they are attracted to the bacteria that are usually negatively charged anionic (-)…

    • 1967 Words
    • 8 Pages
    Better Essays
  • Good Essays

    MicroOrganism

    • 777 Words
    • 4 Pages

    The purpose of this experiment is to distinguish and indentify an unknown bacterium. There are several tests that can help one eliminate and narrow down the options. The most useful test, and the very first one done, is a gram stain. This test will tell whether the bacterium is gram-positive or gram-negative. After the type of gram stain is identified, the tester has a wide array of differentiating tests at their disposal. Based on the results from these tests, and the numerous others that are available, one can accurately establish the identity of an unknown bacterium.…

    • 777 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    Lab 4

    • 890 Words
    • 4 Pages

    Procedure: After setting up the incubator, I aseptically transferred S. epidermidis and L. acidophilus. to generate liquid broth cultures. After waiting for 24-48 to observe growth, I recorded my observations. Then, I prepared wet mount slides and direct staining slides of both S. epidermidis and L. acidophilus. to observe them microscopically using oil immersion lens. When I was done, I stored them in the refrigerator for future use.…

    • 890 Words
    • 4 Pages
    Satisfactory Essays
  • Good Essays

    Unknown Lab Report

    • 1149 Words
    • 5 Pages

    Prepare two slides for gram staining and viewing under a microscope. {Either my gram-stain slides were bad or the microscopes I chose for viewing were not good. No bacteria were found under the microscope.}…

    • 1149 Words
    • 5 Pages
    Good Essays
  • Better Essays

    Tortora, G., Funke, B., & Case, C. (2010). Staining Techniques. Retrieved April 25, 2015, from http://www.cliffsnotes.com/sciences/biology/microbiology/microscopy/staining-techniques…

    • 1286 Words
    • 4 Pages
    Better Essays
  • Powerful Essays

    Observing Blood Lab

    • 1841 Words
    • 8 Pages

    It took some practice to achieve competency with using the microscope; however, once this was accomplished it was much faster and easier to locate and focus on the desired specimen. It also took practice in adjusting the light source so as to have the proper contrast and brightness. In the end the practice using the prepared slides allowed for clear observation of the various bacterial cell shapes such as cocci, bacillus, and spirillium. These shapes were more easily identified in the prepared slides and this knowledge was used to view similar structures in the fresh yogurt slide. Finally, analysis of a blood smear was interesting because it was initially very hard to focus due to the cell mobility. This proved to be the result of too much pressure amongst the slide when using the oil immersion lens and after some practice it was fascinating to view the thousands of red blood cells under the microscope. There were no nuclei present in the red blood cells but the concave nature of the cells did provide for a deeper colored…

    • 1841 Words
    • 8 Pages
    Powerful Essays
  • Good Essays

    The first and easiest data to record is the color of the bacterial colonies on a nutrient agar plate. Growing the cultures on the agar can be done by streaking a plate so as to isolate the bacterial colonies. Then separate the two colonies that are different in growth on a TP plate by using the same streaking techniques with a sterile loop. Both bacteria will then undergo a simple stain and a gram stain. The simple stain uses the charged portion of a chromogen and allows it to act as a dye where it becomes positively charged as a result of picking up a hydrogen ion or losing a hydroxide ion. Thus, the cell becomes colored. The simple stain is useful for identifying the shape of the unknown bacteria. A gram stain is also performed on the unknowns. The gram stain first uses crystal violet as the primary stain. Iodine is then used as a mordant fixodent to lock the stain in. Ethanol is used to decolorize the cell. Safarin is then used as the counter stain in order to show a contrast between the two colors. If the bacteria cell is…

    • 1159 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Identify Unknown Microbes

    • 550 Words
    • 3 Pages

    The two streak plates made from the mixture of unknown bacteria showed two different colony morphologies. Colonies of Bacteria A were translucent in color, circular in form, with entire margins and a smooth surface. Colonies of Bacteria B were cream colored, irregular in form, with undulate margins and an umbonate surface. Two different morphologies allowed Gram stains to be performed on each of the bacterium.…

    • 550 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Observing Bacteria

    • 1135 Words
    • 5 Pages

    Purpose: The purpose of this lab was to display knowledge of the use of a compound microscope with and without an oil immersion lens while observing and identifying various bacterial shapes and arrangements, including a self prepared yogurt culture.…

    • 1135 Words
    • 5 Pages
    Good Essays
  • Good Essays

    As I recall from earlier that semester, the first test that needed to be performed was the Gram stain. The Gram stain is a staining technique that aids in distinguishing cell wall characteristics and the cellular morphology. Bacteria will stain Gram positive, which is a purple color, or Gram negative, which is a pink color. Also, the Gram stain can help to identify the shape of the bacterium. The three basic shapes are cocci, bacilli and spirilli, which means that cocci are berry shaped, bacilli are rod shaped and spirilli are spiral shaped. My unknown bacteria stained purple which means that it is Gram-positive and was berry shaped meaning that the bacterium is cocci. These results have led me to the next step for me to master, the catalase test.…

    • 749 Words
    • 3 Pages
    Good Essays