Electrical impedance spectroscopy (EIS) system

A quality system for researching biological systems

Impedance spectroscopy is a technique used to measure cell size, type discrimination and other quantitative characteristic information of biological systems. At Micronit we manufacture Electrical Impedance Spectroscopy (EIS) chips that offer the advantage of acquiring this information from cells without the need to label them, as would be necessary for characterisation using tools such as fluorescence microscopy. Commercial applications exist, e.g. EIS is used for bacterial, pollen and blood cell counting.

Key advantages of this technique in the microfluidic environment include:

  • Fast throughput: ¬ 1000 cells;
  • Multiple parameter analysis;
  • Integrates well with other analysis methods (i.e. optical detection);
  • Label free analysis method.

A joint effort: Micronit, Zurich Instruments & Fluigent

In order to provide the  best system for our customers investigations and characterisation of various particle types, Micronit joined forces with two innovative companies: Zurich Instruments AG and Fluigent SA. By utilising the Fluigent flow activation and control technology, the stable flow of particle suspensions though our EIS-chip is guaranteed. Whilst the use of Zurich Instruments’ high precision HF2IS Impedance Spectroscope provides a versatile measurement system of electrical signals for characterisation and monitoring.

Validation experiments

To highlight the capabilities of this co-developed system, several validation experiments were carried out. Which had the following conclusion: in general, the use of Micronit’s EIS-chip and connection system in conjunction with Fluigent’s MFCS-Flex flow control equipment and the Zurich Instruments’ HF2IS Impedance Spectroscope enables detection and discrimination of individual cells or particles in flow. In addition, the system can even distinguish different particle sizes and in the case of cells, provide information on the cell’s properties, thereby helping to discriminate cell types.