Inoculating pr glucose broths with organisms

Assignment Help Biology
Reference no: EM1396307

Phenol Red (PR) Broth is a differential test medium prepared as a base to which a carbohydrates is added. Included in the base medium are peptone and the pH indicator phenol red. We will inoculate PR Glucose Broths with three organisms to determine their fermentation characteristics.

Q1. Suppose you innoculate a PR broth with a slow-growing fermenter. After 48 hours, you see slight turbidity but score it as (-/-). Is this result a false positive or a false negative? Is this a result of poor specificity or poor sensitivity of the test system?

Q2. Early formulations of this medium used a smaller amount of carbohydrate and occasionally produced false alkaline (pink) results after 48 hours. Why do you think this happened? List at least two steps, as a microbiologist, that you could take to prevent the problem.

 

Reference no: EM1396307

Questions Cloud

Determining the coefficient of coincidence : Recessive mutant alleles of an x-linked gene in Drosophila, crossveinless, prevent the development of supporting structures in the wings.
Use chi square analysis to test your model : use chi square analysis to test your model - how could you explain this inheritance at the molecular level.
Illustrate what is the marginal cost of the fifth worker : Illustrate what is the marginal cost of the fifth worker? Based on your knowledge of marginal analysis, explain how many workers should you hire?
How would batesian mimicry have an affect on ecology : How would batesian mimicry have an affect on ecology.
Inoculating pr glucose broths with organisms : Phenol Red Broth is a differential test medium prepared as a base to which a carbohydrates is added. Included in the base medium are peptone and the pH indicator phenol red.
Elucidate the steps you conducted in completing assignment : Is beta an accurate measure of risk? Explain why or explain why not? Is the Fama-French model a better model in elucidating securities' returns? Explain why or explain why not?
Completing the introductory statistics course : A university has found that 20% of its students withdraw without completing the introductory statistics course. Assume that 20 students have registered for the course this semester.
How would you make buffer solution : You have stock solutions of 10 M KCl and 100 mM HEPES buffer, pH 7.5. You are asked to prepare a 100 mls of 100mM HEPES buffer containing 0.35 mM KCl. How would you make this buffer solution?
Illustrate what is the required return : Stock Values The next dividend payment by Mosby, Inc., will be $2.45 per share. The dividend are anticipated to maintain a 5.5 growth rate, Forever. If the stock currently sells for $48.50 per share, illustrate what is the required return?

Reviews

Write a Review

Biology Questions & Answers

  Find the titer of b-d-galactosidase

find the titer of B-D-galactosidase using the enzyme-linked immunosorbent assay.

  What is the equilibrium frequency of the resistant allele

How does your answer make clear that why antibiotic resistance evolves so fast. What is the equilibrium frequency of the resistant allele in the absence of methicillin.

  Adopted dna as a useful molecule quite independently

He says that the mere presence of DNA is not sufficient to prove the point: his cells may have adopted DNA as a useful molecule quite independently of all other known life forms. What would you do to convince him that he was wrong.

  Design an experiment to test hypothesis

Assume you are testing a hypothesis that population density of a particular plant species influences the rate at which a pathogenic fungus infects the plant.

  Immediate spatial relationship of the left kidney

Determine what of the following describes the immediate spatial relationship of the left kidney to other structers on posterior abdominal?

  What type of cellular injury occurred in this patient

Describe why organisms only reproduce their own kind, and why offspring more closely resemble their parents than unrelated individuals of the similar species.

  Difference between spermatids and sperm cells

What is the difference between spermatids and sperm cells? What is the name of the transformation of spermatids into sperm cells?

  Importance of adp levels within the mitochondrion

Determine the importance of ADP levels within the mitochondrion, particularly with respect to respiratory rate?

  Counter the same person occur in nature

Discuss how do you counter the same person who says that if the process does occur in nature, there is no such thing as natural selection, but it requires a designer to carry out those specific steps?

  Question about biology innovation

Over the long period of time that life has existed on Earth, there have been number of important or significant innovations including endosymbiosis to create mitochondria and chloroplasts.

  Hardy weinberg equilibrium

For both visual and blind predators, estimate what p will be by the 20th generation. If p > 1, then at what generation was one reached?

  Finding proportion of the offspring

During a cross between organisms having genotypes of AaBbCc and AaBbcc, what proportion of the offspring would be expected to be aaB_Cc?

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd