High-throughput microfluidic single-cell trapping arrays for biomolecular and imaging analysis.

Single-cell analysis is of critical importance in revealing population heterogeneity, identifying minority sub-populations of interest, as well as discovering unique characteristics of individual cells. Microfluidic platforms work at the scale comparable to cell diameter and is suitable for single-cell manipulation. Here we present a microfluidic trapping array which is able to rapidly and deterministically trap single-cells in highly-packed microwells. This chapter first describes the design and fabrication protocols of the trapping array, and then presents its two representative applications: single-cell mRNA probing when integrated with a dielectrophoretic nanotweezer (DENT), and live-cell real-time imaging when combined with fluorescence lifetime imaging microscopy (FLIM). As the single-cell trapping efficiency is determined by the channel design instead of the flow rate, this trapping array can be coupled with different microfluidic sample processing units with different flow rates for various single-cell analyses.