Conclusion
In this paper, we present a bacteria isolation method using elasto-inertial microfluidics, consisting of a two turn spiral channel design for separating viable bacteria from diluted blood at high efficiency and throughput. In this work, we use viscoelastic buffer to sheath the diluted blood sample to the outer wall of a spiral and demonstrate for the first time that blood cells remain fully focused at the outer wall throughout the entire spiral length while bacteria continuously migrate due to the dean vortices for efficient separation. The viable bacteria are recovered free of blood cells and readily available for downstream analysis. In this work, we address one of the main challenges of miniaturization for sepsis application: the trade-off between separation efficiency and throughput. Here, we demonstrate separation of E.coli from 1mL of blood in 40 minutes at an efficiency of 82% using a label-free, passive method. The microfluidic platform opens up possibilities of effectively and rapidly separating viable bacteria from blood at throughputs unmatched using existing microfluidics methods and should warrant clinical value as a stand-alone sample preparation method in clinical settings.