Gram Staining Lab Report

It 's bad or infectious bacteria that cause illness as they rapidly reproduce and produce a toxin that kills or mutates cells, bacteria is also self sufficient.

In the Voges-Proskauer test, I inoculated the tube with bacteria from my TSA plate and incubated the tube at 37 degrees Celsius for 3 days. After three days I placed some Barrits Reagent A and Barrits Reagent B in the test tube. The color change of red or pink indicates a positive reaction for acetoin which tells you that the organism is a butanediol fermentor.

faecalis, S. simulans, or M. luteus. The bacteria could not have been B. cereus because B. cereus is the only Gram-positive bacteria that has a bacillus morphology, this characteristic of B. cereus is not in accordance with the results obtained from the compound biological microscope. A lactose fermentation test was performed to rule out the possibility of the bacteria being E. faecalis or S. simulans if the results were positive for acid production, or rule out the possibility of the bacteria being M. luteus if the results were negative for acid or gas production. After a 48-hour incubation period, the results for the lactose fermentation were negative for lactose fermentation and no acid or gas production was seen in the test tube or Durham tube. A sucrose confirmation test was performed to confirm the identity of M. luteus. After a 48-hour incubation period, the sucrose fermentation confirmatory test was negative, showing no signs of acid or gas production indicating that the unknown bacteria colony was M.

After heat-fixing, I stained with Crystal Violet for 1 min, rinsed with distilled water, stained with Gram Iodine for 1 minute, rinsed with distilled water, gently rinsed with 95% ethanol, rinsed with distilled water again, stained with Safranin for 1 minute, rinsed with water, and dried the slides with bibulous paper. I checked the bacteria with Microscope 90. For the rest of the lab, I performed different tests on the two different bacteria.

-B1 was a Gram positive bacillus that did not show growth on the EMB plates.

From one of my modified streak plates I was able to successfully isolate my Gram positive bacteria. By my 6th plate, there was a distinction between my Gram positive and Gram negative in morphology. To make sure it was absolutely pure I continued to streak it two more times. Once I had a pure plate, I Gram stained it twice to confirm that it was a pure Gram positive coccus. Once it was pure I proceeded to do the catalase test, the bacteria produced bubbles, indicating a positive result. From there I was able to narrow down my unknown to a possible of 4 bacteria. By analyzing my matrix I was able to determine that by doing an Oxidase test, it would eliminate Micrococcus luteus. However, the oxidase test turned positive, allowing me to confirm that my unknown Gram positive bacteria was Micrococcus

After allowing the two unknowns to incubate on the streak plate (Picture B), the next step was to gram stain, and hopefully separate them. After following the procedures for gram staining, and observing my slide underneath the microscope, it was evident that I had two microbes on my slide. One of the microbes was gram positive with a coccus shape, while the other was gram negative with a small rode looking shape to it (Picture A). The next step was to be able to separate them from each other using selective media. For the gram positive unknown, I used a MSA plate, which prevented gram negative growth. For the gram negative unknown, I used an EMB plate, which would inhibit any gram positive growth. The next class period on 4/18/17, my gram negative

The smear concentration will directly affect the gram results by making a false positive or false negative gram positive stain. Take the slide smears and put them in crystal violet solution for one minute. Rinse all of the stain off with water. After all the water has been removed from the slide, place it in the mordant which is Grams iodine solution. A mordant is an inorganic oxide that chemically reacts with the dye and affixes to the cell. Rinse the solution off with water the same way we did before and then place the slide in a decolorizing agent for 10-12 seconds. As not to wait for a long time, rinse this off with water as well. Waiting to wash the decolorizing solution off will clear all the dye of off the previously dyed cells. Put the slide in the counter stain safranin for one minute and rinse with water. Place the slide on bibulous paper and wipe an access water of the slide being careful not to disrupt the bacterial culture. Now that the slide is done, put it under the microscope with an oil immersion to view under 100x magnification. Gram positive bacteria is blue or purple and gram negative bacteria is red or

Bacillus are part of the prokaryotic cell family containing a thin layer of peptidoglycan; however they are spore forming; this trait helps to identify them as “gram-positive”. Step (1) in the staining process is adding the sputum to the slide, step (2) is applying heat to the sample, step (3) adding crystal-violet dye which turns the cytoplasm cells purple and applying mordant to the specimen, step (4) wash with de-coloring solution (alcohol) which causes the peptidoglycan to become more impermeable crystal –violet and iodine, step (5) counterstain is absorbed and is masked by the primary purple dye that was previously absorbed by the “gram-positive” cells (pg. 86). It’s during this step when the microbes are identified.

Most bacteria are harmless, or essential to life. Bacteria help keep the digestive tract working appropriately in the human body. There are also strands of bacteria that can cause hundreds of illnesses, they can do this in several ways. Bacteria can destroy tissue directly, or reproduce on such a large scale that the body cannot function as it should. Bacteria can rapid produce, dividing into two every twenty minutes if in the correct conditions. They reproduce by binary fission in which the single bacterium cell divides into two identical daughter cells. They reproduce asexually.

6. There are bacteria everywhere but we do not get sick from them all the time due to our immune systems. Our immune systems are constantly fighting intruders in the body that can be considered hostile. Once the bacteria is identified by the body special immune cells literally attack and eat the bacteria. By using the chemical markers which were present in that bacteria the immune cells which identify threats can then be prepared to identify them in case of for another

Bacteria are single-celled minute organisms found inside and outside our bodies. Most bacteria is very useful and good for us such as the bacteria found in each person’s digestive tract. This bacteria is important as it breaks down food so that nutrients can be absorbed and it also helps to fight the bad bacteria that causes infection and disease. Bacteria that is not good for us causes infection such as tuberculosis, ear infections, pneumonia and even food poisoning. This is disease causing bacteria. It is not only bacteria that cause illness however, as some infections such as colds and flu are caused by

This report represents my individual effort. I did not receive or offer aid to anyone when performing this assignment, nor did I plagiarize any material.

Bacteria are both good and bad. Without bacteria we would die, but some bacteria could easily kill us: it all depends which ones they are. The good ones, those we need to survive, are there to digest our food (in our intestines) and to live on our skin and in our mouth. By doing so they provide a protection against bad bacteria, that make you sick, and these are called 'pathogenic bacteria'. (Skipor)

Gram Stain: The Gram Stain test was performed on our unknown bacteria and the results were negative. Meaning that the cell wall of the bacteria did not retain the purple dye, therefore it classified it as Gram-negative (-). After observing the slide under the microscope, (Figure 1 below) our bacteria’s morphology was identified as rod-shaped/bacillus.