System and method for monitoring cardiomyocyte beating, viability and morphology and for screening for pharmacological agents which may induce cardiotoxicity or modulate cardiomyocyte function

Abstract

Extracellular recording devices with reference electrodes positioned in a cell free zone and methods of conducting extracellular recording. Parallel cell-substrate impedance monitoring and extracellular recording of excitable cells such as excitable cells, cardiomyocytes, and cardiomyocyte precursor cells using devices that switch between extracellular recording and impedance monitoring modes.

What is claimed is: 
     
         1 . A device for extracellular recording of cells, the device comprising:
 a) a nonconductive substrate forming a base of one or more wells;   b) a recording electrode positioned on the substrate within the well, wherein the recording electrode is accessible to cells when a cell sample is added to the device; and   c) a reference electrode positioned within the well in a cell-free zone, the cell-free zone characterized as free from contact with cells when the cell sample is added to the device, thereby preventing contact between cells and the reference electrode.   
     
     
         2 . The device according to  claim 1 , wherein the recording electrode comprises an electrode structure comprising a plurality of electrode elements. 
     
     
         3 . The device according to  claim 1 , wherein the reference electrode is positioned on the substrate in the cell-free zone. 
     
     
         4 . The device according to  claim 1 , wherein the cell-free zone is defined by a barrier, which prevents cell access to the cell-free zone. 
     
     
         5 . The device according to  claim 1 , wherein the cell-free zone is characterized as being on a different plane than the recording electrode, thereby preventing cell migration to the cell free zone. 
     
     
         6 . The device according to  claim 1 , further comprising at least two impedance electrodes capable of monitoring impedance of the cells, the at least two impedance electrodes positioned within a well and on the nonconductive substrate, wherein the at least two impedance electrodes are accessible to cells when a cell sample is added to the device. 
     
     
         7 . The device according to  claim 6 , operably linked to a system comprising an impedance analyzer, extracellular recording amplifier and switching means capable of switching measurement between the at least two impedance electrodes and the extracellular recording electrode and the reference electrode. 
     
     
         8 . A device for parallel impedance monitoring and extracellular recording of cells, the device comprising:
 a) a nonconductive substrate forming a base of one or more wells;   b) at least two impedance electrodes capable of monitoring impedance of the cells, the at least two impedance electrodes positioned within a well and on the nonconductive substrate;   c) an extracellular recording electrode positioned on the substrate within the well and a reference electrode, wherein the recording electrode is electrically coupled to the reference electrode for performing an extracellular recording measurement at the recording electrode.   
     
     
         9 . The device according to  claim 8 , wherein the at least two impedance electrodes each have the same surface area and each comprises an electrode structure comprising a plurality of electrode elements. 
     
     
         10 . The device according to  claim 8 , wherein the recording electrode is one of the at least two impedance electrodes and the reference electrode is an external electrode free from contact with the non-conductive substrate. 
     
     
         11 . The device according to  claim 8 , wherein the reference electrode is one of the at least two impedance electrodes. 
     
     
         12 . The device according to  claim 8 , loaded with a cell sample, wherein cells within the cell sample contact the at least two impedance electrodes but do not contact the reference electrode. 
     
     
         13 . The device according to  claim 8 , operably linked to a system comprising an impedance analyzer, extracellular recording amplifier and switching means capable of switching measurement between the at least two impedance electrodes and the recording electrode and the reference electrode. 
     
     
         14 . A method of extracellular recording of a cell population, the method comprising:
 a) providing the device according to  claim 1 , operably linked to a voltage amplifier;   b) adding a cell sample to the device, wherein the reference electrode remains free from contact with cells from the cell sample; and   c) performing extracellular recording measurements by amplifying the voltage signals between the recording electrode and the reference electrode and monitoring the amplified signals.   
     
     
         15 . The method according to  claim 14 , wherein the cells comprise cardiomyocytes or cardiomyocyte precursor cells, the method further comprising adding a compound suspected of affecting a beating cycle of the cells and monitoring changes in beating using the extracellular recording. 
     
     
         16 . A method of parallel extracellular recording and impedance monitoring of a cell population, the method comprising:
 a) providing the device according to  claim 8  and operably connecting the at least two impedance electrodes to an impedance measurement circuitry and connecting the recording electrode and the reference electrode to a voltage amplifier;   b) adding a cell sample to the device;   c) performing extracellular recording measurements by amplifying the voltage signals between the recording electrode and the reference electrode and monitoring the amplified signals; and   d) monitoring cell-substrate impedance between the two impedance electrodes.   
     
     
         17 . The method according to  claim 16 , wherein the cells comprise cardiomyocytes or cardiomyocyte precursor cells, the method further comprising adding a compound suspected of affecting a beating cycle of the cells, and monitoring changes in beating using the extracellular recording and monitored impedance. 
     
     
         18 . The method according to  claim 16 , wherein the impedance is monitored at milli-second time resolution.