Electronic continuous growth follow-up of microbial cultures

An apparatus for the measurement of bacterial growth is described. This instrument applies an alternate adequate current of two different frequencies through a pair of electrodes immersed in a cultured medium. It monitors, detects and quantifies the growth of microorganisms based on the measurement of the impedance across the two electrodes, from which medium conductivity and interface electrode impedance changes can be dissected out. The variation of these parameters are proportional to bacterial growth. They are processed by this computer controlled apparatus and displayed on a monitor showing bulk resistance and electrode impedance variations as time course events.