512 channel system for in-depth insights into complex cell electrophysiology
The PCOR system was built as part of the joint research project PhenoCor. It combines very high channel counts, multi modal electroanalytical measurement techniques and a novel design approach for integration into bioanalytical and medical research environments.
For a detailed view into the electrophysiological properties of cell-based assays the system includes a range of measurement options:
- Complex electrical impedance spectroscopy (EIS)
- Electrophysiological (cell) potential measurements (EFP)
- Electrical Impedance Tomography
- Complex Electrical Stimulation
- Temperature measurements
- Additional control and sensing options
The functions are assigned to 512 measurement channels and a customizable set of additional (e.g. stimulation, reference, biasing) electrodes. All 512 measurement channels can be configured to impedance or potential measurement mode. The key features of these measurement channels are:
- Software programmable low impedance current measurement or high impedance potential measurement on all 512 measurement channels
- Fully simultaneous/parallel data acquisitions on all 512 measurement channels
- High precision complex impedance measurements up to 1 MHz
- Low noise Electrophysiological potential measurements with up to 50 kSPS
- EIT measurements with up to 100 fps
Electrical stimulation can be configured freely (steps, pulses, ramps, sinusoidal, arbitrary) on up to 4 independant stimulator channels. Mapping of these stimulator channels onto the sensor electrodes is done through the sensor specific functional multiplexing situated inside the sensor adapter. The functional multiplexing also handles assignments for reference or biasing electrodes.
On top of that the system can be extended with other measurement modules, e.g. a high frequency impedance analyzer or potentiostat to allow even more versatile sensing options.
The system is segmented into 4 major components:
- A system controller including high performance computing hardware and extentable mass storage.
- A measurement unit including all measurement modeules as well as low level controls
- A sensor adapter attached to the measurement unit providing the interface to the sensor plate
- The actual sensor that can be placed onto the sensor adapter
For cell based assays, cultivation as well as monitoring/measurement is best done in high quality incubators under temperature and CO2 control. While the system controller is a benchtop unit sitting outside of the incubator, the measurement unit and sensor adapter are small enough to fit onto a typical incubator shelve. They are designed for use inside of the incubator making long time (continuous) measurements without introducing instability into the cell culture possible. The systems´ sophisticated thermal management ensures controlled transfer of any excess heat from the measurement unit to the outside of the incubator without impacting thermal stability of the sensor or other materials inside the incubator.
The initial reference application for the system is a high density clinical research assay for a better and more precise in-vitro stratifization, model-based therapy planning and clinical safety pharmacology for patients suffering from a genetically caused heart disease (refer to the PhenoCor project for more details). However, the system is designed for being adapted to other sensors and bioanalytical assays. For that purpose the sensor adpater and the sensor carrier can be easily customized for various sensor geometries and functional electrode assignments. Additional interfaces within the sensor adapter even allow for extensions like fluidic control, thermal management, mechanical manipulation or additional sensors (e.g. optical).