Hello!
I was wondering if its possible to know what is the maximum OD that the pioreactors are able to detect in a culture? I have been limiting the OD at around ~1 but aiming to increase the density of my cultures, so I was curious if there is a hard limit that the pioreactors stop detecting OD accurately 
Hi @ucl_star!
It’s unfortunately difficult to say without trying some local tests. Each culture scatter IR light differently, or changes morphology at high densities, etc. that it’s hard for us to provide a single number. What you’ll see first is some non-linearity, and then when you go beyond that, you’ll see a decrease in signal.
You can perform some tests locally to check when this non-linearity starts. Performing an od_calibration provides you with a graph of the linear-region and non-linear region. You don’t have to use the calibration after it’s done, too.
The idea of ^ is just to take a high density culture of known OD600, record what the Pioreactor says, dilute it down, and repeat.