Oxygen transfer by orbital shaking of square vessels and deepwell microtiter plates of various dimensions

Oxygen transfer rates (OTRs) during orbital shaking were measured for differently sized polypropylene vessels that were either square or round in the horizontal plane, using an enzymatic method involving glucose oxidase, horseradish peroxidase (HRP), and 2,2-azino-bis 3-ethybenz-thiazoline-6-sulfonic acid (ABTS). In comparison to non-shaking conditions (3.2 mmol O-2 l(-1) h(-1)), OTRs in 4 mm x 4 mm vessels (corresponding to wells in 384-square deepwell microtiter plates) at a working volume of 0.125 ml could only be significantly enhanced at 300 rpm if a shaking diameter of 50 mm was applied (25 mmol O-2 l(-1) h(-1)) instead of 25 mm (6.7 mmol O-2 l(-1) h(-1)). Larger square vessels (18 mm x 18 mm and 50 mm x 50 mm) yielded high oxygen transfer rates and a regular shaking pattern, demonstrating that vessels in this size range could be a viable, space-efficient, alternative to baffled or unbaffled Erlenmeyer shaking flasks. Round vessels (internal diameter 6.6 mm) resulted in OTRs that were approximately 50% of those measured for square vessels in the same size range. (C) 2003 Elsevier B.V. All rights reserved.