title: Continuous scalable blood filtration device using inertial microfluidics.
abstract: Cell separation is broadly useful for applications in clinical diagnostics, biological research, and potentially regenerative medicine. Recent attention has been paid to label-free size-based techniques that may avoid the costs or clogging issues associated with centrifugation and mechanical filtration. We present for the first time a massively parallel microfluidic device that passively separates pathogenic bacteria cells from diluted blood with macroscale performance. The device was designed to process large sample volumes in a high-throughput, continuous manner using 40 single microchannels placed in a radial array with one inlet and two rings of outlets. Each single channel consists of a short focusing, gradual expansion and collection region and uses unique differential transit times due to size-dependent inertial lift forces as a method of cell separation. The gradual channel expansion region is shown to manipulate cell equilibrium positions close to the microchannel walls, critical for higher efficiency collection. We demonstrate >80% removal of pathogenic bacteria from blood after two passes of the single channel system. The massively parallel device can process 240 mL/h with a throughput of 400 million cells/min. We expect that this parallelizable, robust, and label-free approach would be useful for filtration of blood as well as for other cell separation and concentration applications from large volume samples.
authors.affiliation: Department of Bioengineering, University of California, Los Angeles, CA, USA.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Mach
authors.forename: Dino
authors.initials: D
authors.lastname: Di Carlo
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D001769:Blood; D002469:Cell Separation / Q000379:methods*; D004864:Equipment and Supplies; D005374:Filtration / Q000379:methods*; D044085:Microfluidics / Q000379:methods*