ABSTRACT
Electrical detection in microfluidic devices provides a means of enumerating, sizing, and characterizing particles or cells without fluorochromes or other dyes. This chapter focuses on electrical impedance-based single-cell analysis performed on micro-fabricated devices in a flow-through manner. It highlights advantages, issues and challenges of miniaturizing microfluidic channels and electrodes. The chapter illustrates some aspects of moving from an academical feasibility study to a commercial product, and thus bestow to single-cell microflow impedance analysis more than just a proof-of-principle status. The pretensions of impedance microflow cytometry as a single-cell analysis tool are easily benchmarked to the achievements and nourished by the prospect that microtechnologies might provide smaller (portable), faster, simpler, and cheaper solutions. One of the most important milestones for developing an impedance-based microflow cytometer was the replacement of the expensive lock-in amplifiers and function generators with dedicated electronic boards and thereby switching to digital data processing.
