Abstract: The present invention relates to a cell culture device (1) comprising a disposable culture vessel comprising at least one external wall made of a material having a Young modulus E of less than 50 GPa, in which there is situated at least one cell culture zone and at least one cell-free medium transfer zone, allowing a flow of a culture medium between the cell culture zone and the transfer zone, and at least one sensor element of a cell-density sensor wherein said sensor element is situated in the cell culture zone of said vessel. The sensor element is an electrode arrangement of at least two and preferably at least four measuring electrodes arranged on the inner side of an external wall of the disposable culture vessel and directed towards the cell culture zone. The present invention further relates to a method of culturing cells.

Abstract: Mixing system comprising: a flexible bag (28) with a mixing device (1) comprising a magnetic impeller; and an alignment facilitation device adapted to facilitate alignment between the magnetic impeller and a magnetic driver (36) located external to the system. Specific flexible bag and hardware therefore.