A generic and label free method based on dielectrophoresis for the continuous separation of microorganism from whole blood samples

摘要

Current methods for the in vitro diagnostics of bloodstream infections are based on blood culture, followed by phenotypic characterization of the pathogen. Nevertheless, such methods are too long in the case where a fast and appropriate medical treatment is needed. There is thus a very strong interest in blood sample decomplexification methods to be coupled to the existing analytical means. In this paper, we report the continuous flow capture and concentration of microorganisms spiked in a blood sample, flowing within a dedicated microfluidic device. The separation is achieved with dielectrophoresis (DEP) forces, using hypotonic conditions for the buffer. We demonstrate efficient and real-time accumulation of target pathogens from blood in our microfluidic device, thus providing a decomplexified sample suitable for further characterization. In particular, up to 97% capture rate could be observed with Escherichia coli micro-organisms. Simultaneous separation of different micro-organisms (Gram+, Gram- and yeast) could also be achieved, showing the versatility of the method and device.