Dielectrophoretic separation of blood pathogens ou Bacterial extraction from biological samples using DEP forces

We report here a method based on DEP separation to concentrate pathogens out of a biological sample by combining positive and negative DEP to separate pathogens from the sample matrix. In this approach, we take advantage from the large tolerance of micro-organisms towards osmotic shock to perform dielectrophoretic separation in a low electric conductivity medium. This condition enables to collect micro-organisms by positive DEP, while lysed blood cells are repelled from the electrodes by negative DEP. Our microfluidic device is designed based on numerical simulation. This approach is validated on a large range of microorganisms, since it has been tested with different species of bacteria (S. epidermidis (Gram +) and E. coli (Gram -)) and yeasts (C. albicans).