Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, 92617, USA.
Department of Medicine, Division of Hematology/Oncology, University of California, Irvine, Irvine, CA, 92617, USA.
Sci Rep. 2017 Aug 31;7(1):10173. doi: 10.1038/s41598-017-10000-1.
Resistive-pulse sensing is a label-free method for characterizing individual particles as they pass through ion-conducting channels or pores. During a resistive pulse experiment, the ionic current through a conducting channel is monitored as particles suspended in the solution translocate through the channel. The amplitude of the current decrease during a translocation, or 'pulse', depends not only on the ratio of the particle and channel sizes, but also on the particle position, which is difficult to resolve with the resistive pulse signal alone. We present experiments of simultaneous electrical and optical detection of particles passing through microfluidic channels to resolve the positional dependencies of the resistive pulses. Particles were tracked simultaneously in the two signals to create a mapping of the particle position to resistive pulse amplitude at the same instant in time. The hybrid approach will improve the accuracy of object characterization and will pave the way for observing dynamic changes of the objects such as deformation or change in orientation. This combined approach of optical detection and resistive pulse sensing will join with other attempts at hybridizing high-throughput detection techniques such as imaging flow cytometry.
电阻脉冲感应是一种无标记的方法，用于描述单个颗粒通过离子传导通道或孔时的特征。在电阻脉冲实验中，当悬浮在溶液中的颗粒通过通道时，监测通过导电通道的离子电流。在易位过程中，即“脉冲”期间，电流幅度的减小不仅取决于颗粒和通道的大小比，还取决于颗粒的位置，而仅通过电阻脉冲信号很难解决这个问题。我们提出了同时进行电和光学检测颗粒通过微流道的实验，以解决电阻脉冲的位置依赖性问题。通过在两个信号中同时跟踪颗粒，创建了一个粒子位置与电阻脉冲幅度的映射，该映射在同一时间点。这种混合方法将提高物体特征化的准确性，并为观察物体的动态变化铺平道路，例如变形或方向变化。这种光学检测与电阻脉冲感应相结合的方法将与其他尝试混合高通量检测技术（如成像流式细胞术）相结合。
