Materials and Methods To start with, the unknown bacteria # 710 broth had to be successfully isolated on an EMB and MAC agar plate. Using aseptic technique by sterilizing the wire loop with Bunsen Burner between inoculations and flaming the opening of the test tubes before inserting in the loop with the bacteria. The streaking technique used was to isolate the colonies on the agar plates. In addition, the streak plates had to be incubated in a upturned position for 24 hours in a hot temperature incubator at 37 degree Celsius. Bacteria need a favorable condition to grow in. After incubation, a gram stain was performed one the colonies that were isolated. First, the organism was smeared onto a slide with a loop full of distilled water. The smear was heat fixed to provide the bacteria to stick to surface. Next, the staining started by using crystal violet for 60 seconds, rinsed with distilled water. Then iodine for 60 seconds, rinsed with …show more content…
The SIM tube was first inspected for black precipitate indicating sulfur reduction and cloudiness around stab line for motility. Kovacs reagent was added in the tube a red color change in the alcohol layer. Red which also indicated is was positive for indole production. Methyl Red is used to determine if an organism is capable of performing a mixed acid fermentation. Methyl Red were added to MR test tube. As the solution becomes acidic it will turn red immediately. A negative result will have no color change. The VP test if the color change was red it indicated a positive results. Citrate test is used to identify if an organism is capable of utilizing citrate as a sole carbon source. Citrate medium contains sodium citrate as the only carbon source. if the bacteria can utilize the citrate it will also convert to the ammonium phosphate to ammonia hydroxide. The test will conclude and the agar will turn blue it means citrate was
Methods Unknown microbial #398 went through several of tests in order to identify its characteristics when isolated from a urine sample of Doris, a 64- year old patient with a kidney infection. To identify unknown #398, must prepare a working and a reserve stock by the inoculation from a broth culture and by quadrant streaking method on a PEM and EMP plates. The following test procedures were incubated at 37°C for 48 hours for observation and identification for unknown #398. The identification of unknown #398 followed test procedures from Brown1.
If the catalase enzyme is present in the organism being tested then when in the presence of hydrogen peroxide (H2O2), the enzyme will convert the solution to water and oxygen, this can be observed bubbling of the organism when hydrogen peroxide is added to the test tube. EMB agar is both a selective and differential media; it is selective for gram-negative cells, in that when a gram-positive culture is plated there will be no colonies after incubation because the eosin and methylene dyes prevent the growth of gram-positive organisms, the
The purpose of this lab report is to employ a myriad of skills, tools and, methods learned throughout this semester to perform the appropriate tests for the identification of the assigned unknown bacteria. Add more background information here!!! The most important tools and techniques used during this identification include aseptic technique, microscopic examination and, the use of selective and differential media. Aseptic technique is an important tool for microbiologists. It is imperative that aseptic technique is maintained throughout the length of any test to avoid any cross-contamination that may lead to inaccurate results.
I expect to learn the biochemical differences in bacteria from this lab. Also, how to identify different species of bacteria. Material & Methods For the first day of the practical, an unknown specimen was provided
1. What new vocabulary words did you come across? What are their definitions? Ambiguous.- having several possible meanings.
Fiona Young Ha Hoang and Joey Lu 12/11/15 Malik AP Chem 4th Prepare to Dye Introduction Chromatography is the separation of a mixture or substance by putting it in a solute with chromatography paper. Following with this lab, we take 3 colors of food dye (red, yellow, and blue) and test which solvent out of distilled water, acetone, ethanol, and 2-propanal would separate the molecules in the dyes the best.
My bacterium turned out to be gram positive. When conducting these tests, I only had to do the coagulase test and the catalase test because when doing the catalase test, the reaction was that it had bubbled. If it did not bubble, or have a positive reaction, then I would not have had to do the coagulase test. Also, since my bacterium caused a positive catalase test, I only had to do the coagulase test and no other tests. This is because with staphylococcus organisms, these are the only tests
It is necessary to understand what each test reveals about the unknown. Citrate tests are performed in order to distinguish between different enteric bacteria by seeing which can use citrate as the sole carbon source. MR/VP are tests that are used to distinguish between different types of fermentation either mixed acid or butanediol and test for the production of acetoin. H2S production is used to determine whether or not the bacteria can produce hydrogen sulfide. Mannitol high salt testing is done in order to determine if the bacteria is salt tolerant and can ferment mannitol.
In a non-reducing sugar 3cm cubed and 10 drops of hydrochloric acid is placed in a test tube for a water bath of 5 minutes to be mixing afterwards. Biurets reagent is added to the protein solution to determine it presence. Testing for
The starch-iodide complex forms because of the transfer of charge between the starch and iodide ion and results in spacing between the energy levels. This allows the complex to absorb light at different wavelengths resulting in a dark blue colour (Travers et al., 2002). A blue colour would indicate a positive test while a yellow colour would show a negative test. The Benedict’s test is useful for reducing sugars.
The sterile cotton swab was inserted in the S. epidermidis culture and twirled around to obtain a specimen. The entire plate was inoculate with the swab from top to bottom, to achieve a lawn of growth. The dry forceps was used to remove the antibiotic disk into the appropriate spot on the plate. This process was repeated for the all antibiotics with aseptic technique being used. The plate was incubate with lid up on the bookshelf at room temperature for 48 hours.
In test tube C , the iodine solution change from brown to dark blue which is different from the expected . It is because the amylase is denatured at 75℃ that the the activity of amylase is low or even stop. Therefore, the starch is not broken down into maltose by amylase. In the test D, a dark-brown solution is seen in the test tube after adding the iodine as the pH of the 1ml 0.5M HCl is not an optimum pH for the activity of amylase that the starch is broken down into maltose . Amylase may not break down the starch well.
5 water bath were set up each to10 °C. (5 were used do the experiment faster) 5 cm3 of starch solution were added into the 5 test tubes that were labeled test tubes. Then 5 cm3 of amylase enzyme was added into the other 5 test tubes that were labeled. Put one of the starch solution test tube (preferably the one labeled 1) and one of the test tube containing amylase into the water bath (10 °C).
From the Unknown tube professor Cooper gave me, I scratched a little on the slant surface with the sterilized inoculating loop. Then I place it on a clean prepared slide which already had a slight drop of water. The two substances are mixed together in the middle of the slide and let dry completely. One extra step of “heat fix” is necessary to adhere everything to the surface of the slide. To start gram staining, I slightly pour crystal-violet all over the slide and let it sit for 30 seconds before wash it off with water.
Then, tests are performed to determine if the products of aerobic and anaerobic respiration are present in the flasks. The citric acid cycle consists of a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins into carbon dioxide and chemical energy in the form of ATP (Biology). The tests detect the presence of carbon dioxide and ethanol. Carbon dioxide should be present irrespective of the type of respiration taking place, but ethanol is present only if fermentation has occurred. Another factor that can indicate whether fermentation occurred or cellular respiration occurred is the amount of glucose utilized during incubation.