Immersible online cell biomass probes have historically suffered from a limited range of linear response to biomass and sensitivity to process variables, such as agitation and gas sparge rate. A new optical probe has been developed that provides linear response over 4 orders of magnitude of biomass (e.g. 0.01 to 200 g/L yeast dry cell weight). The small probe diameter (e.g. 3 mm) and minimal optical penetration depth (e.g. < 3 cm) make it suitable for a wide range of vessel types, including miniature bioreactors (e.g. 250 mL). Interference from bubbles is largely eliminated through a novel measurement technique, making the results nearly insensitive to agitation and aeration rate changes. Learn More