To facilitate and speed up process- and media development, online measurement techniques for shake flasks accompany manual sampling for maximum information output per cultivation. Off-gas analysis gives oxygen transfer rate (OTR), carbon dioxide transfer rate (CTR) and respiratory quotient (RQ) as quantitative measures of the physiological state of the culture. On shake flask scale, multiple cultivations are usually run in parallel. Off-gas analysis should therefore be cost effective, easy to handle and versatile to match various applications. Therefore, we developed a shake flask off-gas analysis system for non-invasive online determination of OTR, CTR and RQ. TOM (Transfer rate Online Measurement) is built modular for off-gas analysis in 4, 8, 12 or 16 individual shake flasks. The new Kuhner TOM can be applied to various shake flask sizes and types (baffled, plastic, glass) enabling the user to get information about their existing cultivation procedures.