For 96-roundwell plates, culture volumes between 0.1 and 0.2  ml are used, preferably at 300 rpm on a shaker with a 50 mm amplitude. This shaking condition leads to oxygen-transfer rates of 20-40 mmol O₂ l^-1 h^-1 (corresponding to k_La values of 100-200 h^-1).

Because surface tension effects start to be relevant at such small vessel diameters (6mm), it is best to use rich (protein-containing) growth media; this lowers the surface tension, and so improves mixing.

For a good mixing, we advice to use no more than 0.15 ml culture volume (or even less if higher oxygen-transfer rates are needed). Such low culture volumes make it difficult to take off the supernatant after centrifugation. A trick to make this easier is to add an equal volume (so e.g. 0.15 ml ul) of water or buffer prior to centrifugation.

Please note that you have little room to manouvre with regard to the shaking conditions: a centrifugal force in the order of minimally 2.5 g (as with 50 mm, 300 rpm) is needed to overcome the surface tension, and so to obtain full mixing down to the bottom of the culture, and prevent “ dead zones”.