How to check how many bacteria were killed?

[hitmankratos]

Lets say we have this bacterial culture in a jelly agar and we want to see how many bacteria would x quantity of a antibiotic kill..Is there a way to get that info?

For example, I have a e.coli culture and want to try amicillin on it and want to know (in % maybe?) how many were killed...

[CharonY]

Basically you would simply count the titer. Either count the whole (live and dead) titer and then count only the surviving part (either usind live/dead stain or plating and counting the survivors). You could also simply split a culture and treat one portion and compare the live titer in each case.

[ecoli]

you could also count CFUs on an agar plate from before and after treatment. This will give you a relative measure.

[CharonY]

That's what I actually meant with live titer...