Measuring Oxygen Transfer Rate (OTR) Of The Eppendorf Fermentation Vessels

By Ying Yang and Ma Sha, Applications lab, Eppendorf Bioprocess Center,

This short protocol describes the procedure to measure the oxygen transfer rate (OTR) of the Eppendorf fermentation vessels, an important parameter of the vessel specifications. It is crucial to measure OTR under industry standard conditions with 1 vessel volume per minute (VVM) of air sparging only without oxygen enrichment, as the increase of VVM or oxygen sparging will significantly inflate OTR values. We used the industrial standard sulfite depletion method for our measurement under maximum agitation and air sparging. In a model experiment, we employed a BioFlo® 320 3 L glass vessel and followed the equation to calculate the mean OTR to be 366.4 mmol O₂/(L×h). This short protocol can serve as a reference for the bioprocess professionals who want to perform OTR measurements of Eppendorf’s large collection of fermentation vessels.