Microfluidic Impedance Cytometry for Blood Cell Analysis

Microfluidic Impedance Cytometry (MIC) is a label-free technique for counting and analyzing single cells at high throughput. Over the last decade the technology has matured into a robust and versatile tool with applications in many areas. Multi-frequency impedance measurements provide information on cell dielectric properties, including cell volume, membrane capacitance, and internal (cytoplasmic) electrical properties. This chapter describes the basic principles underlying MIC together with the technology that enables such measurements. Examples of application in healthcare and diagnostics are provided, including the use of MIC for performing a fast and simple full blood count with a very small volume of sample. The limits of sensitivity of the system are discussed along with novel approaches to enable measurement of small particles such as bacteria. MIC has been used to probe the properties of parasite infected cells, to distinguish tumor cells from normal cells, and even in the differentiation state of stem cells. Addressing future technology challenges, particularly in integrated sample processing, should enable MIC to be used as part of a simple diagnostic toolkit providing sample in, answer out solutions.