Introduction
Staining is used in a variety of ways in order to color the background of a cell, discern types of cells and to discern structures of a cell. A differential stain is when multiple dyes are used to stain a cell that take advantage of chemical differences in a cell. Gram staining is a type of differential stain that works by distinguishing gram positive and gram negative cells by coloring them violet or red, respectively. Gram positive cells contain a thick cell wall of peptidoglycan and a single membrane. Gram negative cells contain a thin cell wall which is located between two membrane layers. There are four reagents used in gram staining which include crystal violet, iodine, ethanol and basic fuchsin. Crystal violet is a primary methyl
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Iodine is a mordant that binds the crystal violet to the cell. Ethanol is a decolorizer that in gram negative, washes away outer membrane and cell wall and in gram positive, collapses the cell wall. Basic fuchsin is counterstain that enters the unstained gram negative cells. Gram staining is a useful method as it is simple and inexpensive to perform and it gives important identification information about bacterial cells fairly quickly. One drawback to gram staining is that some cells can be gram variable because the age of the culture can influence the results. When cells are gram variable, it is difficult to tell if the culture is contaminated, or just old. Gram staining was devised in 1882 and published in 1884 by Danish bacteriologist Hans Christian Gram. In the medical field, gram staining can be used on bodily fluids to determine if there is a
Upon receiving the unknown Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes. After ten minutes had passed, I collected the ingredients needed to perform a gram stain. I got the primary stain, crystal violet, and flooded my smear for sixty seconds, and then rinsed the color off with water until the water ran clear. I then flooded the smear with the mordant, grams iodine, and let that sit on the slide for sixty seconds as well. I then rinsed the grams iodine off with water and applied alcohol to the smear to decolorize the cells; however I made sure not to over decolorize and only put enough drops on the smear till the purple ran clear. I then rinsed the slide with water and flooded the smear with safranin the counter stain and let it sit for sixty seconds and then rinsed the color off with water. I blo...
As the solution pH can influence the stability of NaClO-NH3 blend and the elimination of SO2, NOx, the impact of the pH of NaClO-NH3 blend solution on the instantaneous removal as well as the duration time was investigated, and the final pH after reaction was also detected and shown in Fig. 5. It can be seen that the variation of solution pH has a negligible effect on the desulfurization, but the elevated pH has a great promotion on the NOx removal, the efficiencies are significantly increased from 36% to 99% for NO2 in the pH range of 5–12 and from 19% to 65% for NO when the pH is between 5 and 10, after where, both of them are constant. Hence, the optimal pH of the NaClO-NH3 solution for the
coli cells were grown at 37 degrees Celsius with calcium ions. These cells were then incubated in ice and placed into 4 polypropylene tubes. Each tube consisted of 25 microliters of E.coli cells. Two of the four were labeled with (+) while the other two were labeled (-). Positive was with samples that contained 100 pg/ microliter of pGLO, while negative was for the samples that did not. The 4 tubes were incubated in ice for 30 minutes, then heat shocked for 30 seconds at 42 degrees Celsius. The 4 tubes were then returned to the ice bath for 5 minutes. After the removal, .975 microliters of LB media was added to each tube at room temperature. The tubes were then shook at 225 RPM at 37 degrees Celsius for one hour. 300 microliters of cells were then extracted from the tubes and then placed in agar plates. The cells were spread across the plate and the incubated overnight at 37 degrees
The first step to the unknown is selecting an actual organism. The best way to select a culture is based on a high-quality distribution. Equally important, shaking up the broth tube facilitates in the distribution. Upon selection, a gram check for purity is performed. Step by step instructions for this procedure can be found in Benson’s, Microbiological Applications p. 99. Furthermore, an aseptic technique must be performed for this test and the entire tests following the unknown. The purpose of this test is to differentiate between gram positive and gram-negative bacteria. The key indicator of gram-positive bacteria is a purple stain and a pink stain for gram-negative bacteria. A slide is viewed with a microscope under oil immersion. Equally
After that bolt the slide dry with bibulous paper. After that examine the slide under the oil immersion lens. After determining the Gram stain reaction, 18 specific biochemical tests were performed for further analysis. The way of biochemical test was different but need to incubate at 37 degree Celsius. Phenol red lactose, phenol red dextrose, phenol red sucrose, methyl red, voges-proskauer, citrate utilization test, urea hydrolysis, and nitrate reduction are the media which are in test tube as liquid. Which were use Inoculating loop to deep tube with assigned bacteria. Triple sugar iron, and citrate utilization are in slant and we use Inoculating needle to deep tube with assigned bacteria. Again, starch hydrolysis, casein hydrolysis, lipid hydrolysis, oxidase test and catalase test were test from agar plate which use inoculating loop. For those media, which were in agar plate, inoculate with loop by making a line streak down the center of the agar. After that all 18 medias need to incubate at 37 degree Celsius for 48 hours. After 48 hours, some media show bacteria’s characteristics and morphology without adding extra reagent. Some media need reagent to examine morphology and physiology. Experiment such as MRVP needs methyl red, Barritt’s A, and Barritt’s
The slide was placed on a staining tray where the sample was stained using crystal violet. After a minute the sample was rinsed. After that Gram iodine was put on the sample and was rinsed again, after a minute. Following that a 95% alcohol/acetone was dropped on the sample until only a faint violet like color is seen. Immediately following that the slide was rinsed in order to prevent further destaining. Then the sample was covered with safranin for 45 seconds in order to restain the destained gram-negative bacteria making it have a purple-pinkish color. Following this the slide was rinsed and the sample was observed.
Testing of Intercellular Material for DNA through Agarose Electrophoresis Purpose: The purpose of this lab was to determine whether or not DNA was actually extracted in the prior week’s experiment, in which E. Coli bacteria’s was lysed and through a series of chemical extractions it’s inner contents were harvested. Methods: 4.5 mL E.Coli EDTA suspension pipetted into a conical tube. After this, 0,25 mL lysosome solution was put inside the same tube. Both were incubated at 37°C for a few minutes. Once out of the incubator, 0.5 mL of 10% SDS was added.
Eosin methylene blue agar (EMB) is a medium used to isolate fecal coliforms and is selective for gram-negative bacteria against gram-positive bacteria. Sucrose and lactose serve as fermentable carbohydrate sources which encourage growth and allow one to differentiate between fermenting and non-fermenting microbes. Vigorous fermenters of lactose or sucrose will produce quantities of acid sufficient to form the dark purple dye complex which is usually associated with a green metallic sheen. Slow fermenters will produce a smaller amount of acid production and appear brown-pink in color (Lab Handout; EMB). This experiment resulted in no color change which was expected as two previous tests indicated that my unknown was a gram- positive bacteria and this test is selective for gram-negative bacteria.
To identify the bacteria under the microscope was not easy since it was our first time identifying bacteria. After one of our trials we would pour a drop of water on to a slide, and then add Iodine Sodium over that because the Iodine helps the bacteria to show more. We would then observe the water and record our qualitative observations, which were ½ from the microscope observation and the other ½ was while watching the water...
Pigments produced by microorganisms has been used to dye fabrics of different types. Talaromyces verruculosus produce a red colored pigment which is suitable to dye cotton and is harmless. Pigments from microorganisms give different types of shades of a color. For instance; Janthinobacterium lividum produce a pigment which gives purplish-blue shade to different types of fabrics. Thermomyces produce a yellow pigment used to dye number of fabrics specifically silk. NP2 and NP$ strains of Streptomyces produce dark blue and red colored pigments. Among retaining dye of microbial strains cotton fabric were stained comparatively weak while acrylic and polyamide fibers stained strongly.
Halitosis is the medical term for Bad Breath. When people think of bad breath they automatically think that food is the cause of the bad odor. When in reality there are many factors that can lead up to bad breath. Yes food is one of them but there are other reasons as to why a person may be experiencing bad breath or teeth staining. A person may experience bad breath or teeth staining because they may have a health problem that is causing the odor other factors are smoking and chewing tobacco.
...h the help of the second buffer which increases the ionic strength of the solution. The charge of the buffer can also be modified to alter the rate of interaction between proteins and the resin. If the proteins are negatively charged at our corresponding given P.H, we should use anion exchange chromatography and if it is positively charged, we should use cation exchange chromatography.
A scientist named Christian Gram invented a technique called gram staining by which is colorized that is separated into two groups Gram positive and Gram negative. In bacteria most have rigid cell walls in which is accountable for the shape of the organism. Within the cell wall of the bacteria it identifies whether the bacteria is gram positive or negative. In the cell wall there a lot of difference that determines the bacteria is gram is positive or negative for example the thickness and the amount of peptidoglycan later presences or absence of outer membrane and teichoic acids. Where gram positive have two later and negative has three layers. Gram positive the cell wall is a single layer, primarily composed of peptidoglycan, does not contain outer membrane and contains negatively charged teichoc acids, this result of a blue color indicator. For gram negative is more complex that the Gram positive, its membrane lies outside of th...
In the late 1800s, Hans Christian Gram developed the gram staining procedure. Gram staining is a valuable diagnostic tool used in the clinical and research world. The gram stain is a method used to determine the identification of unknown bacteria. (BIO215, 2017)
Experiment #3: The purpose of this experiment to test the chromatography of plant pigments the alcohol test strip test will be used.