Question

In Chapter 21, we performed the plaque assay in which the T4 bacteriophage was used to infect E. coli strain B cells. Select one of the scenarios below, indicate the expected result, and describe what could have caused the observed result.

1. You are asked to repeat the plaque assay using the T4 bacteriophage with E. coli strain B. After a 24 hour incubation period at 37°C, you observe no plaques on all of your plates.
2. You are asked to repeat the plaque assay using the T4 bacteriophage with E. aerogenes instead of E. coli strain B. After a 24 hour incubation period at 37°C, you observe plaques on all of your plates.
3. You are asked to repeat the plaque assay using the T4 bacteriophage with E. coli strain B. After a 24 hour incubation period at 37°C, you observe no growth on all of your plates.

Answer 1

I chose Scenario 2, If Bacteriophage is grown with bacteria E.aerogenes (or E.coli), Bacteriophage immediate attack on its replication or hacked its machinery to produce its offspring, They produce 100 plagues per cell and bacterial cells die at this moment while Phage still appears because of it survive around 4-80 'C. So, in the end, we observe that after 24 hours no bacterial colony observe on plate while phages or plaques observe on plates.