1). A cis test of two T4 rll mutants yields 1000 plaques on E. coli B and 10 plaques on E. coli K12. Assume neither mutant grows on strain K12. The lysate from the initial coinfection was diluted 5x before addition to E. coli B. a. What is the viral titer (plaque forming units per volume plated)? Assume 1mL was plated and use plaques per 1mL as the units. b. Do you need to use the rule of two here? Why or why not? c. What is the distance (m.u.) between the two mutants? d. What can you conclude about the two mutants?

1). A cis test of two T4 rll mutants yields 1000 plaques on E. coli B and 10 plaques on E. coli K12. Assume neither mutant grows on strain K12. The lysate from the initial coinfection was diluted 5x before addition to E. coli B. a. What is the viral titer (plaque forming units per volume plated)? Assume 1mL was plated and use plaques per 1mL as the units. b. Do you need to use the rule of two here? Why or why not? c. What is the distance (m.u.) between the two mutants? d. What can you conclude about the two mutants?

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter17: Bacterial And Viral Genetics

Section: Chapter Questions

Problem 1ITD

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Considering counting rules, calculate the initial titre of the sample viral stock if the following plaques were counted in a plaque assay. Show clear sample calculations. Table 1: Plaque assay counts for lambda phage stock titre enumeration of average concentration (PFU/mL) Total dilution of viral stock 1/13500000 1/135000000 1/135000000 plated Volume diluted viral stock 0.1 0.1 0.1 plated (mL) PFU replicate 1 TNTC 275 25 Calculated concentration (PFU/mL) replicate 1 PFU replicate 2 TNTC 239 23 Calculated concentration (PFU/mL) replicate 2 Average concentration (PFU/mL)
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