To produce plaques, a lawn of bacteria is grown, then phage are spread on it. Is there any disadvantages?

what are the disadvantages (if any) when growing the lawn before spreading the phage (bacteriophage)?

To produce plaques, a lawn of bacteria is grown, then phage are spread on it. Is there any disadvantages?
At the very least, it takes an extra day to see results. You can spread the bacteria, then spread the phage right afterwards and have your plaques the next morning.
Reply:1. the bacteria might overpopulate the dish making the plaques hard to see/nonexistant and therefore, messing up your results. So the phage may still be eating the bacteria but it may not show because there are way too much bacteria on the plate.





2. Some kinds of bacteria may only survive for a very short period of time with the nutrients provided on the plate (sometimes not even a day). You may have "old" bacteria or the bacteria may have lived out its lifespan by the time you spread the phage. This could mess up the results of the tests. You want to use bacteria that are "in the prime of their life" for your tests because bacteria metabolise differently according to their life stages.





Those are all that I can think of right now. Hope it helps.