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Is titer of E. coli irrelevant for MS2 plaque assay? - (Jun/19/2007 )

This is my first time doing a plaque assay of any kind. The protocols I have read for MS2 propagation basically use general terms when it comes to how much E. coli to use for the overlay agar, such as a drop or two from overnight culture. Being a person who wants to know specific details, I'm wondering if it is more accurate/valid to know exactly how many CFUs I'm adding to make the lawn of E. coli. I know the final outcome of PFUs of MS2 is what's important, but being as we're going to be using the plaque assay to obtain our raw data (we're trying to eliminate MS2 from water by chemical means) and not just using it to propagate MS2 and titering it, wouldn't our data be more valid if we knew exactly how much E. coli we used to make our plates? Or am I totally thinking too much into it and is the E. coli titer irrelevant? As long as I have a lawn of cells (drop or two).....



Okay, I've got the answer....
Seems that the titer is irrelevant because the bacteria will grow to a lawn of cells on the plate until they've exhausted all the nutrients and therefore stop growing. So whether I add one drop or two of a liquid culture to the agar plate doesn't matter because a lawn of cells can only grow so far anyway. But thanks for looking! smile.gif