marinerush

Isn't 33 microliters of bacterium in 300 microliters of medium a 1/10 dilution? --> 33/333 = 1/10? Either way, say we measure the growth rate (cell count) over a period of time for each dilution factor (eg. 10^-1, 10^-2, 10^-3, etc) Obviously the 10^-3 dilution will have a lower cell count at the end of the period compared to the 10^-1 dilution. What I'm asking is what could be the reason for this? 1. Is it because of the actual initial dilution factor of the bacterium? 2. Or is it because of the dilution factor of the spent media? And ultimately, what would be the best way to figure out which reason it is?

So I start different dilutions. I would do 10^-1, 10^-2, 10^-3 and so on. If you could imagine like 10 wells. I would transfer 33 microliters from the 10^-1 well to the next one, making it a 10^-2. So as I go further into dilution of the bacterium, the spent media is also decreasing. I start growth and end growth at the same time for all of these dilutions, but for some reason I see more growth after 24 hrs in the 10^-1 dilution than the 10^-5 dilution of bacterium.

So I'm currently growing 5 bacterial cell cultures. I start at the dilution of 10^-1 by adding 300 microliters of a media and 33 microliters of the bacterium. So when we do these dilutions fewer cells are developed. Is it because we are starting with fewer cells or is it because we are using less spent media?