ABSTRACT
Adherent cells can be expanded in number by plating, or seeding, a culture dish with a low density of cells (Figure 5.1a) and then maintaining the culture to allow the cells to attach (Figure 5.1b) and proliferate enough to nearly cover the culture surface (Figure 5.1c). When the cells cover the entire culture surface, the culture is said to be con§uent. Once a monolayer culture is nearly con§uent, cells are dissociated from the surface and neighboring cells using the proteolytic enzyme trypsin and replated at a lower density in multiple culture dishes (Figure 5.1d). The process of transferring cells from one culture vessel to another to allow further growth is called subculturing or passaging. By subculturing primary cells, an early passage cell line is established (Freshney 2010).
