Microwave Interferometric Cytometry for Signal Analysis of Single Yeast Cells

Abstract

Microwave dielectric sensing offers a rapid, label-free, and non-invasive way of characterization and sensing of biological materials at the microfluidic scale. In this work, a dielectric sensing is achieved with a microwave interferometric setup that is applied to cytometric applications. A fast way to analyze and design an interferometric system at microwave frequencies in software tools is proposed together with a novel manufacturing and assembly process, which enables a short recovery time and avoids extensive microwave-microfluidic chip fabrication. The simulation and measurement results of the interferometric setup are in agreement with an excellent match at levels below S21 = −60 dB. The sensitive microwave setup is evaluated on measurements of 3 µm polystyrene spheres and finally applied for characterization of a widely used laboratory Saccharomyces cerevisiae strain, the S288C, in a frequency range from 4 to 18 GHz.

Keywords

• single cell
• interferometer
• permittivity
• yeast
• microfluidics