I'd really appreciate your help. I'm working with Synechococcus. In my experiment, I have Synechococcus in a solution of milli-Q water. I illuminated it with a focused white light through a pinhole and observed it using a CCD camera. The Synechococcus flows downward, which I think is due to gravity. But, in time, the Synechococcus flows downwards at an angle. Is this due to heat convection? If it is heat convection, it's strange that it sometimes stops flowing. The only visible motion seems to be Brownian motion.
Thank you your help!