During some cultivation experiments for my bachelor thesis I noticed that in liquid culture my bacteria (E. coli) grew differently, according to the position in the shaking incubator.
Because the goal was just to induce protein expression at a given OD, I altered the position of the flasks in the shaker, so the cultures were at a similar OD and I could add the IPTG to all of them at the same time.
Now I wonder if someone else noticed this phenomenon (Literature to cite would be great, I couldn't find anything until now) or if I did something wrong. Maybe it's also known and ignored for longer times? The cultures more in the back of the incubator grew faster, so I think it's because of temperature alterations when opening the incubator to draw samples for growth kinetics, but I'm not sure about this at the moment.
Thank you for helping me :-)