Tech Note

Optical Density: Understanding Cell Concentration and Closed-Loop Perfusion Control

Cell density is a critical variable in all cell culture because it can affect outcomes such as cell growth, cell phenotype, and protein titers. Traditional cell density monitoring involves daily sampling and staining, which is labor and time consuming. To overcome this challenge and enable hands-free monitoring with robust control, bioreactors may be outfitted with sensors to measure cell density and allow close-loop control of the process.