Abstract: The present invention relates to a method of expanding pluripotent stem cells (PSC) in suspension culture in a bioreactor, the method comprising (i) adding an inhibitor of ROCK (ROCKi) to pluripotent stem cells being cultivated in suspension in the bioreactor; (ii) adding a cell dissociation agent, thereby dissociating aggregates of the pluripotent stem cells; (iii) diluting the cell dissociation agent added in step (ii) by adding an excess volume of culture medium sufficient to decrease the concentration of the cell dissociation agent to a concentration at which cell aggregates can form again; and (iv) culturing of the mixture obtained in step (iii) under suitable conditions that allow the expansion of the PSCs.

Abstract: The present invention relates to a method of changing culture medium of a suspension culture, the suspension culture comprising cells suspended in the culture medium, the method comprising: (i) transferring a fraction of the suspension culture into a container, wherein the container comprises at least one opening at the bottom; (ii) allowing the cells comprised in the fraction of the suspension to settle at the at least one opening at the bottom of the container by gravitation, thereby forming a supernatant; (iii) dispensing the cells settled at the bottom of the container (back) into the suspension culture; (iv) discarding the supernatant.