Electro-disruption of Escherichia coli bacterial cells on a microfabricated chip

A miniaturized system for sample preparation of relevant bacterial pathogens has been developed using a variety of microfabrication techniques. The system manipulates and disrupts Eschericha coli bacterial cells using dielectrophoresis, electroporation and enzymes. The microchip consisted of circular gold electrodes patterned on glass using standard photolithography housed in a PDMS chamber. The bacterial lysis efficiency by electroporation and enzymatic degradation was evaluated on the microchip. The miniaturized system was capable of concentrating and aligning bacterial cells in regions of high electric field by dielectrophoresis. The miniaturized sample preparation system had a lysis efficiency of 17% when the bacterial cells were suspended in a 0.25 M sucrose solution and increased to 80% when the bacterial cells were suspended in a solution containing 0.25 M sucrose and 10 KU/ml lysozyme. Sample preparation is a limiting factor for the successful application of molecular pathogen detection methods. Therefore, the development of miniaturized systems useful for sample preparation will improve molecular detection methods of bacterial pathogens.