As an antibody company, Rockland Immunochemicals chooses cell-culture conditions that optimize antibody production. The company considers the volume of antibodies to be produced (e.g., a small amount of less than 5 mg or a larger amount of more than 100 mg), starts growing cells in a T-flask and then expands the cultures up to the most appropriate vessel size. “Don’t always assume the bigger the vessel, the larger the yield,” cautions Eckert. “Sometimes the smaller flasks on the market do just as well or better than large flasks. We prefer flasks that are specially treated for tissue culture with vented caps for maximum cell adhesion and easy CO2 exchange for the cells.” Indeed, different volumes or types of vessels have different venting characteristics. For example, larger quantities of cells grown in suspension might grow better in roller bottles, which allow more gas exchange. “You can also perform roller bottle production with non-vented caps in which the cells produce their own CO2 within the bottle,” says Eckert. “Therefore they can be in culture without the use of CO2 and can culture upwards of 30 days in culture.”