Department of Biomedical Engineering, Lund University, Ole Römers väg 3, 22363, Lund, Sweden.
CNRS, Univ. Bordeaux, CRPP, UMR 5031, 115 Avenue Schweitzer, 33600, Pessac, France.
Sci Rep. 2020 Feb 28;10(1):3670. doi: 10.1038/s41598-020-60338-2.
Handling of submicron-sized objects is important in many biochemical and biomedical applications, but few methods today can precisely manipulate this range of particles. We present gradient acoustic focusing that enables flow-through particle separation of submicron particles and cells and we apply it for separation of bacteria from blood lysate to facilitate their detection in whole blood for improved diagnostics. To control suspended objects below the classical 2µm size limit for acoustic focusing, we introduce a co-flowing acoustic impedance gradient to generate a stabilizing acoustic volume force that supresses acoustic streaming. The method is validated theoretically and experimentally using polystyrene particles, Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli. The applicability of the method is demonstrated by the separation of bacteria from selectively chemically lysed blood. Combined with downstream operations, this new approach opens up for novel methods for sepsis diagnostics.
在许多生化和生物医学应用中，处理亚微米级别的物体非常重要，但目前很少有方法能够精确地操作这个范围内的颗粒。我们提出了梯度声波聚焦，能够实现亚微米颗粒和细胞的流动式粒子分离，我们将其应用于从血液裂解物中分离细菌，以促进它们在全血中的检测，从而改善诊断效果。为了控制低于经典声波聚焦 2µm 尺寸限制的悬浮物体，我们引入了一个共流声阻抗梯度，以产生稳定的声体积力，抑制声流。该方法使用聚苯乙烯颗粒、金黄色葡萄球菌、肺炎链球菌和大肠杆菌进行了理论和实验验证。该方法的适用性通过选择性化学裂解血液中细菌的分离得到了证明。结合下游操作，这种新方法为脓毒症诊断开辟了新的途径。
