Electrical Impedance Spectroscopy Pack

As the analyte enters and exits the differential electrode pairs in a microfluidic chip, a peak and a trough in current are observed. With a differential input, the signal from the surrounding fluid is suppressed, meaning each cytometry event can be resolved with reduced noise.

Continuous flow microfluidic devices with embedded microelectrodes for electrical measurements can be employed for detecting and classifying single cells or particles (e.g. beads or droplets) in a high throughput manner. Further, since the dielectric properties of a biological cell are defined by its cellular characteristics such as cell volume, composition and architecture, impedance spectroscopy can be used to differentiate between cell types. When using impedance spectroscopy, the frequency response of the cell can be measured and fitted to an equivalent circuit model. This allows quantitative measurements related to the different properties of the cell to be extracted, such as membrane thickness and cytoplasm conductivity. Moreover, it is also possible to perform precise droplet analysis using EIS (droplet size, counting, cell-in-droplet quantification).

Han, Z. et al (2020) proposed a microfluidic impedance flow cytometry device with a constriction microchannel for simultaneously characterizing the mechanical and electrical characters of plant cells at the single-cell level. 

Particularly, by using the Electrical Impedance Spectroscopy Pack together with impedance analyzers from Zurich Instruments, two characteristic parameters, passage time and impedance opacity, were extracted as biophysical parameters to specify the deformability and membrane electrical property of single plant cells, respectively. 

Taken together, this study provides a high-throughput system for rapid and sensitive biophysical characterization of plant cells at the single-cell level and it also envisions the development of more powerful biosensors for single cell phenotyping, which could complement the traditional approaches to obtain a more comprehensive view of gene functions.

The Importance of Pressure-Based Flow Control

Control flow rate with the benefits of responsive, pulse free flow

Pulse-free flow is critical for generating high quality and repeatable results. The Flow EZ™ integrates the all-new DFC (Direct Flow Control) algorithm which allows the user to set a flow rate directly on the instrument display. The applied pressure will automatically adjust to maintain the flow rate.