Rapid Automated Bacterial Impedance

Microbial metabolism results in an increase in both conductance and capacitance causing a decrease in impedance and a consequent increase in admittance. In the Rapid Automated Bacterial Impedance Technique (RABIT) system, the admittance was plotted against time to provide results (Bolton, 1990). The final electrical signal is frequency- and temperature dependent and it has a conductive and a capacitive component. At present, impedance instruments are able to detect 10 —10 bacteria/ml (Ivnitski et ah, 2000). Several commercially available systems are operated... 

Fehlhaber, K., and Kruger, G. (1998). The study of Salmonella enteritidis growth kinetics using rapid automated bacterial impedance technique. /. Appl. Microbiol. 84,945-949. 

Several commercial analytical instruments are based on this principle. These systems include the Bactometer (BioMerieux, Nuertingen, Germany), the Malthus system (Malthus Instruments Ltd., Crawley, UK), the Rapid Automated Bacterial Impedance Technique (RABIT Don Whitley Scientific Ltd., Shipley, UK), and the Bac-Trac (Sy-Lab, Purk-ersdorf, Austria). However, these measurement systems are not suitable for on-the-spot applications, so many efforts have been made to minimize the instruments [3]. 

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