S.X. Simon, H. Markewich, E. Mallick, M. Weber
Keywords: dielectrophoresis, pathogen, electroosmosis, microfluidic, electronics
Summary:Fluid-Screen, Inc. presents a bacterial capture and sorting method based on dielectrophoresis (DEP) and electroosmosis (EO). These electronic phenomena have been known to influence particle motion and capture since the 1960’s, however, technology based on DEP or EO has historically had low efficiency, limiting its use for practical applications. Fluid-Screen has developed a novel electrode that induces high electric field gradients to make use of DEP and EO for bacterial capture. The design of this sample-sorting electrode allows for rapid and efficient isolation of diverse bacteria from a variety of aqueous solutions. Furthermore, by precisely controlling electronic conditions, the Fluid-Screen device can differentially process distinct types of bacteria for selective manipulation. The technology has applications in biodefense; the municipal, recreational, and environmental water industries; clinical diagnostics; and sterile manufacturing quality control. The Fluid-Screen sample sorter captures both Gram-positive and Gram-negative bacteria, along with those lacking a cell wall. Notably, it works with bacteria of a range of sizes. In addition to fluorescent laboratory-defined strains of bacteria, environmental, and bacteria endogenous to a sample respond to the electric field. Furthermore, bacteria behave differently from larger particles such as human red blood cells, opening the possibility of using the technology for sterilization or filtration applications to selectively remove bacteria from a contaminated source. Bacteria are either attracted to or repelled from the Fluid-Screen sample sorter based on the applied frequency and voltage of the electric field, allowing for controlled capture and release. By selectively isolating and immobilizing bacteria from fluid, the sample sorter concentrates bacteria from a low-titer sample for low-volume release and transport into any number of bacterial detection or identification systems. This allows for real-time detection of bacterial contamination without time-consuming amplification methods. Although current Fluid-Screen designs are optimized to capture bacteria, the electrode feature design may be customized to capture and manipulate other particles such as viruses, proteins, and chemicals for efficient sample preparation prior to detection.