Entry-level Device for Online Biomass Measurement in Shake Flasks

SFR vario BM

The SFR vario BM offers non-invasive online monitoring of biomass in your shake flask culture, and additionally measures temperature and rpm. Optical biomass measurements are based on scattered light detection, so no integrated sensors are necessary. The biomass data can be correlated with parameters like optical density, cell dry weight or cell concentration, so you are able to get real-time information on e.g. OD600 development. This inexpensive entry-level device is capable of later expansion to measure O2 and pH (requires hardware changes at PreSens). With the respective software license, it has also OPC functionality. The device can be used with any flask from 125 to 5000 mL volume. The system has two rechargeable batteries, and is compatible with any standard shaking incubator. Measurement data is transferred wirelessly via Bluetooth to a PC / notebook, so there are no cable connections inside or outside the shaker. Up to 4 SFR vario BM can be controlled simultaneously with the PreSens Flask Studio software and the wireless data transfer gives you more flexibility in setting up the devices, e.g. in different shakers, while they are controlled from one PC.

  • Measure biomass online in your shake flask culture
  • Most cost-effective system on the market
  • Proven SFR vario technology
  • Expansion options for O2, OUR & pH measurement
  • Optional OPC functionality
  • Parallel measurements in up to 4 shake flasks
  • Wireless data transfer enables easy and flexible integration
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Biomass Monitoring in E. coli Culture

E. coli MG1655 were cultured in 500 mL shake flasks and the biomass and temperature monitored online with the SFR vario BM. The temperature graph shows how the medium equilibrates with the set temperature in the shaking incubator. After about 5 h the bacteria show exponential growth that lasts for about 9 h. After that, the maximum biomass seems to be reached.

Online Monitoring of Yeast Culture

S. cerevisiae was grown in 2 L shake flasks and the biomass development monitored with the SFR vario BM. After 55 h of cultivation, a small peak in the biomass measurements indicates a metabolic shift to consuming another substrate. At this point, growth stagnated temporarily. The continuous measurements with SFR vario BM delivered a more detailed view of culture performance during the different growth phases.

Biomass Measurements in Plant Cell Suspension Culture

Optical biomass measurement was performed in suspension culture of S. fruticosa cells. These plant cells do not form large aggregates when kept in suspension culture, which otherwise might interfere with optical biomass measurements. The data obtained with the SFR vario BM shows the continuous growth of the cells. Maximum biomass was reached after about 200 h of cultivation.


Measuring range Optical Density OD600 1 - 80 (typically)
Temperature sensor range

From - 40 °C to + 85 °C


Compatibility Glass or plastic shake flasks from 125 mL to 5000 mL volume (with respective universal clamp)
Power supply Nickel-metal hydride batteries 7.2 V / 2700 mAh (Use only the delivered battery charger for recharging!)
Digital interface Bluetooth, USB to Bluetooth adapter included
Dimensions 145 mm x 173 mm x 44 mm
Weight w/o batteries: 1110 g
w/ batteries: 1660 g
Operating & storage temperature + 5 °C to + 40 °C
Relative humitdity 0 to 85 % (non condensing)
Max. shaking frequency 250 rpm

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