Q: Methyl red test Does a Phenol red organism have to be methyl red?
A: It is required to find if the Phenol Red organisms are also Methyl Red in the indicator tests.
Q: Explain why only gram-negative cells undergo decolorization during the gram staining procedure.
A: Gram staining is a method in which cells stain either pink (gram-negative) or purple (gram-positive)…
Q: The gelatin medium required inoculation with 3 loopfuls of culture. Why was so much organism…
A: Gelatin hydrolysis test is carried for detecting the ability of the bacteria to produce protease…
Q: What is this test? What coated the bottom of the wells? What were we testing for? How did we know it…
A: The test is ELISA. It is an Enzyme linked Immunosorbant Assay, which is used in many applications.…
Q: Isolating a pure culture from a mix sample is typically done on solid agar but can be performed…
A: A microbial culture is a method of multiplying microbial organisms by letting them reproduce in…
Q: how many coliform colonies would you expect to see on your 1:10 plate? Your 1:100 plate? Explain.
A: Introduction Coliform is the gram-negative, non-spore-forming and motile or non-motile bacterial…
Q: What are the 2 most important reasons for using a positive control in Microbiology tests? What are…
A: A control test is used to set a reference for comparison in microbiological tests. It helps the…
Q: Explain the mechanism leading to the given reactions in the inoculated biochemical media. 1.…
A: Triple Sugar Iron test (TSI) is a microbiological test carried out in differential medium to test a…
Q: Why is it important to keep the culture at the correct incubation temperature when measuring the…
A: Generation time is the time which is taken by the bacteria to double in number during a specified…
Q: Transillumination is used clinically for the detection of:
A: Transillumination is an examination that is done with the help of a strong light shining on a…
Q: Samples subjected to a test were given. Determine the reagent/material in the test. Methyl…
A: Different chemical tests use different reagents and apparatus depending on their working principle.
Q: Why would the optical tweezers be a method superior to dilution and liquid enrichment for obtaining…
A: Optical tweezers have been used to trap dielectric spheres, viruses, bacteria, living cells,…
Q: What are pure cultures and why are they important? How are spread plates, streak plates, and pour…
A: In science and related fields, a culture plate is a low level lined lab holder for growing a layer…
Q: In a Kligler Iron Agar/Triple Sugar Iron test you end up with a result with a yellow butt and red…
A: When a non-lactose fermenting bacterium hydrolyses the agar slant in the Kliger Iron Agar/ Triple…
Q: ake a look at your streak plate from the use of a mix culture. Does your plate show the results that…
A: The streak plate method is a microbiological technique used for the isolation of pure strain ;…
Q: Drawings of the two bacterial cultures as observed under the 4 mm objective. Describe features…
A: Staphylococcus aureus and Streptococcus pyogenes are gram positive bacteria that cause infections in…
Q: Differentiate Widal from Weil-Felix test.
A: The Weil-Felix test detects typhus and specific rickettsial infections. Rickettsia is bacteria…
Q: Use the differential test matrix for this question. You are performing a single unknown. You have…
A: Methyl red test is as also called as MR test. This test is used to determine if the organism…
Q: Explain the effects of ampicillin and X-gal in the following 4 different LB media plates LB LB +…
A: Ampicillin provides a means of selecting transformants that have taken up plasmid DNA containing the…
Q: What is the color result of 1% solution of casein, Albumin, Gelatin in ninhydrin test? Include…
A: Ninhydrin test: Chemical test to detect presence of ammonia, primary/secondary amines, or amino…
Q: Choose the dyes or reagents used in the Endospore stain. (More than one choices are correct) a…
A: Simple stains- A stain that employs a single stain to color a bacteria: they are quick and easy.…
Q: Biochemical and differential tests can be incorporated into growth media or performed on isolated…
A: It is required to provide three examples of differential test that is incorporated into growth media…
Q: A serial dilution of overnight E.coli culture was performed by pipetting 1ml of a bacterial culture…
A: A growth medium is intended to promote the growth of a variety of microorganisms or cells by the…
Q: What side of the electrophoresis chamber (red or black) should the wells be on when the gel is…
A: The agarose gel electrophoresis is a technique that is used to separate DNA fragments as per their…
Q: Nitrate reduction to nitrite is indicated by the formation of a pink to red colour after addition of…
A: Sulfanilic acid reacts with nitrous acid to form diazotized sulfanilic acid if introduced. This…
Q: You saw no color change in both the first step and second step of the Nitrate Reduction test. What…
A: A nitrate reduction test is a test done to test whether the Enterobacteriaceae member produces the…
Q: The following figures are the photomicrographs of the samples taken with Kern&Sohn Camera Microscope…
A: Ans: Lugols solution: The Lugols solution is 2.5 to 25% weight by volume total iodine.
Q: Below I have attached the image of gram stain. -We need to find the name of the compound. And after…
A: Gram negative bacteria - The bacteria which are unable to retain crystal violet stain in the process…
Q: Why does the oxidase test must be performed from blood agar or another medium without a fermentable…
A: Biochemical tests are used to identify microbial diversity based on variations in the biochemical…
Q: In the preparation of a pure culture media, the petri plates are inverted when placed in an…
A: In microbiology, culture media is considered the growth medium that possesses the specific mixtures…
Q: A 10-2 is performed on a culture of bacteria in order to perform viable plate counts. From the…
A: CFU means colony forming unit. It is a measure of viable bacterial or fungal cells. In case of…
Q: Which test require a straight line inoculation? Choose all that apply. A) Bile esculinase B) NaCl…
A: Inoculation is a form of immunisation that involves the introduction of an infectious material onto…
Q: Starting with 10 bacterial cells per milliliter in a sufficient amount of complete culture medium…
A: Bacteria are organisms that are found almost everywhere on earth and are free-living cells that are…
Q: What are the colour changes occur to the reducing sugars after benedict test is performed? Please…
A: Reducing sugar is a sugar that is capable to act as a reducing agent. Reducing sugars are the ones…
Q: You can perform a specific staining method to confirm the purity on the culture. Describe this…
A: Staining methods are used to differentiate between two bacteria depends on their cell wall. To…
Q: Can culture media be sterilized in the hot air oven? why or why not?
A: Sterilization is the process of deactivating, killing, or removing any kind of microorganism (or…
Q: You were instructed to add 1.0 mL out of 4.0 mL of an undiluted sample to 99 mL of sterile diluent.…
A: The dilution factor can be defined as the ratio of Volume of the initial solution to the volume of…
Q: What is the main difference between plates before and after centrifugation? What may be the purpose…
A: Answer: CENTRIFUGATION = It is the process involving mechanical force that is centrifugal force,…
Q: The first step in identifying an unknown bacterium is to __________. culture your unknown on…
A: Bacteria are the minute microorganisms that are unicellular and have a cellular level of…
Q: Plating 0.1 mL of a sample diluted by a factor of 10^(-3) produced 43 colonies. What was the…
A: The question asks the original concentration (OCD) is to be identified in an undiluted…
Q: To measure the culture temperature, why is the thermometer placed in a tube separate from the…
A: A microbe or microorganism is a microscopic organism that is too small to be seen with the naked…
Q: What could be possible errors when you incorrectly identify an Unknown organism when using IMViC…
A: IMViC tests are used to identify bacteria from specimens collected from patients in majority of…
Q: If the seven-digit profile that is tabulated cannot be found in the API® 20E Analytical Profile…
A: The API® 20E System, is a biochemical panel for identifying and differentiating members of the…
Q: purpose of the Methyl Red and Voges-Proskauer Test. What makes each one unique and why?
A: The methyl red reagent is a solution that detects the acidic pH of the culture. Voges-proskauer test…
Q: Why are plated media stored in an inverted position?
A: Plated media enables the isolation of microorganisms from samples or specimens.
Q: A mistake was made in preparing the arginine decarboxylase test, and mineral oil was NOT added to…
A: * Decarboxylation test is for anaerobic reactions hence mineral oil is to be added to the broth to…
Q: In preparing bacterial smear, why do we need to pass the slide over the flame?
A: since this is a multi-part question, so I am answering only 1st part. please upload other questions…
Q: If you were using the quadrant streak plate method to plate a very dilute broth culture (with many…
A: Streak plate technique is the technique or method that is widely used for the isolation of a pure…
Q: In RPR test, Why is it necessary to rotate the slide/card?
A: RPR stands for Rapid Plasma Reagin. It is done to detect syphilis.
Q: To dilute a bacterial culture, 500 μl of a 16 hour culture is mixed with fresh culture media to a…
A: Given Values: Volume of the 16 hour culture = 500 μl Final Volume of the culture media = 5 ml
WHY IN INDOLE TEST A COLORED RING FORM AT THE TOP OF THE CULTURE MEDIA BUT NOT THE WHOLE CULTURE MEDIA COLOR CHANGE?
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- Nitrate reduction to nitrite is indicated by the formation of a pink to red colour after addition of nitrate test reagent. However, if a culture does not produce a colour change several posibilies exist. Explain.How would you prepare a 10-7dilution from a culture? Each of your dilution tubes cannot hold more than 1mL.What is the result for the yellow tube of Methyl red test? What must the pH be in each tube? What is the reagent used in this test? What media is used? Describe the biochemical abilities of these organisms .
- Which is the better reagent for the clinical test between Fehling's solution and Benedict's solution? Explain briefly the answerWhat are the advantages of the API 20E test compared to regular biochemical tubemediaWhy does the oxidase test must be performed from blood agar or another medium without a fermentable sugar as MacConkey agar?
- Which stationary phase is better in separation of the components of moringa extract for column chromatography? Sodium Bicarbonate or Silica Gel? And Explain.Voges Proskauer test Does color of the medium change to red after both reagents were added and allowed to sit for 60 minutes? If yes, after about how many minutes before you can see red color?Why should the use of nichrome or iron containing loop/wire be avoided as an inoculating device when performing the oxidase test in microbiology lab?
- Isolating a pure culture from a mix sample is typically done on solid agar but can be performed using a liquid media. How can you isolate a pure culture from a mixed culture in a liquid medium (broth, not agar)?What is the amount (mL) of pre-culture (108 cell/mL) necessary to inoculate (to add) in a 2-liter culture media for a concentration of 6.5 × 106 cells/mL?What medium is this? What is the result in tube at left? In second tube? What does it tell you about the biochemical abilities of these organisms? What is the reagent used to detect the red?