Abstract

Node-Pore Sensing: A Versatile Microfluidic Method for Performing Single-Cell Analysis

Lydia Sohn, Professor, Department of Mechanical Engineering, University of California, Berkeley

We have developed an efficient, label-free method of screening cells for their phenotypic profile, which we call Node-Pore Sensing (NPS).  NPS involves measuring the modulated current pulse caused by a cell transiting a microfluidic channel that has been segmented by a series of inserted nodes.  When segments between the nodes are functionalized with different antibodies corresponding to distinct cell-surface antigens, immuno-phenotyping of single cells can be achieved.  By simply inserting between two nodes a “contraction” channel through which a cell can squeeze, we can simultaneously measure a cell’s size, resistance to deformation, transverse deformation, and ability to recover from deformation.  Finally, replacing the contraction channel with one that is sinusoidal such that a cell undergoes periodic deformation results in measuring a cell’s viscoelastic properties.  In this talk, I will describe the many applications of NPS we are pursuing—from immuno-phenotyping leukemic blasts to distinguishing chronological age groups of primary human mammary epithelial cells to identifying white vs. brown adipocytes—all based on mechanical properties.  I will also describe the development of the next-generation NPS platform which utilizes advanced signal processing algorithms directly encoded in the NPS channels to thus achieve multiplexing.