Cells with intact plasma membranes in a fermenter can be considered to act as tiny capacitors under the influence of an electric field.

The non-conducting nature of the plasma membrane allows a build up of charge. The resulting capacitance can be measured: it is dependant upon the cell type and is directly proportional to the membrane bound volume of these viable cells.

Aber’s technology converts capacitance into a live biomass reading, typically cells/ml or g/l. However, other units can be derived from the raw capacitance measurements; these may be more relevant to the chosen application.

FUTURA also measures the Conductivity of the medium, in millisiemens per centimetre (mS/cm). Conductivity is not used to measure biomass but is indicative of the production or utilisation of ions by the cell suspension, e.g. pH control and other fermentation processes.