Figure 5.

(a) Diagram of a spinner flask. It is commercially available and can either be reusable (glass) or disposable (plastic). The stir bar can be magnetic or a rotating paddle, rotating from 20 to 120 rpm, but optimal rotational speeds are determined empirically. The lid could also incorporate a porous membrane through which oxygenation can occur. (b) Schematic diagram of a rotating wall bioreactor. The inner cylinder usually has a porous membrane that allows oxygenation. There are commercially available products, with volumes ranging from 10 to 500 mL, but custom-made bioreactors are also in use. Scaffold sizes of up to 10 cm³ are reported in the literature. Typical rotational speeds in slow turning lateral vessels (STLVs) range from 5 to 36 rpm.³²