Patch clamp electrophysiology
To evaluate single ion channel conductance, a microelectrode forms a high resistance seal with the cellular membrane, and a patch of cell membrane containing the ion channel of interest is removed. Alternatively, while the microelectrode is sealed to the cell membrane, this small patch can be ruptured giving the electrode electrical access to the whole cell. Voltage is then applied, forming a voltage clamp, and membrane current is measured. Current clamp can also be used to measure changes in membrane voltage called membrane potential. Voltage or current change within cell membranes can be altered by applying compounds to block or open channels. These techniques enable researchers to understand how ion channels behave both in normal and disease states and how different drugs, ions, or other analytes can modify these conditions.
Patch-clamp workflow using Axon Instruments
The Axon Instruments® portfolio provides comprehensive solutions for patch-clamping that includes amplifiers, digitizer, software, and accessories. Our best-in-class instruments facilitate the entire range of patch-clamp technique experiments from the smallest single channel to the largest macroscopic recordings. The addition of Axon pCLAMP 11 Software Suite creates a streamlined workflow, allowing for sophisticated and effecient experiments, and higher quality data generation Learn more about the electrophysiology lab set up >
- Prepare solutions – Make internal and external solutions. Adjust osmolarity and pH values.
- Prepare cells or brain slices – Prepare cultured cells, isolated neurons, brain slices, or whole animals.
- Pull and polish the pipette – Prepare the recording electrode. Pull the glass capillary tube and polish pipette tip.
- Set up the perfusion system – Set up the perfusion system and data acquisition software. Ensure that the system is shielded.
- Patching a cell – Use the manipulator to touch the cell membrane with the pipette. Ensure a high resistance electrical seal is formed.
- Signal acquisition and amplification – The signal will be amplified. For best results, ensure you are using the correct type of amplifier for your research.
- Signal digitization – The analog signal is then digitized so that the signal can be analyzed.
- Data acquisition and analysis – With pCLAMP 11 Software Suite, longer and more sophisticated protocols can be programmed for faster data analysis and precise measurements.
Quick links to Patch clamp electrophysiology basics:
Learn more about patch clamping techniques, from single channel to whole cell to extracellular field-potential recording.
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Action Potential
An action potential is a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern. Examples of cells that signal via action potentials are neurons and muscle cells.
Action Potential
An action potential is a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern. Examples of cells that signal via action potentials are neurons and muscle cells.
Cellular Pathway Analysis
Ion channels are involved in many cell pathways and understanding the function of ion channels in response to changes in membrane potential or the presence or absence of other molecules is important in order to understand exactly how ion channels participate in normal and abnormal biological processes such as cell differentiation and migration, disease states, and neuronal communications.
Cellular Pathway Analysis
Ion channels are involved in many cell pathways and understanding the function of ion channels in response to changes in membrane potential or the presence or absence of other molecules is important in order to understand exactly how ion channels participate in normal and abnormal biological processes such as cell differentiation and migration, disease states, and neuronal communications.
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cSEVC
What is continuous single-electrode voltage clamp (cSEVC)? It is an electrophysiology patch-clamp method that passes a membrane voltage into a cell and measures the change in current as the voltage steps.
cSEVC
What is continuous single-electrode voltage clamp (cSEVC)? It is an electrophysiology patch-clamp method that passes a membrane voltage into a cell and measures the change in current as the voltage steps.
Current Clamp Amplifier
Current-clamp is a method used to measure the resulting membrane potential (voltage) from an injection of current. To measure the membrane potential, the MultiClamp 700B and Axoclamp 900A both monitor voltage drop initiated by current injection along an in-series resistor. Current-clamp is commonly used to inject simulated, but realistic current waveforms into a cell, and monitor membrane effect. This technique is ideal for the evaluation of important cellular events such as action potentials.
Current Clamp Amplifier
Current-clamp is a method used to measure the resulting membrane potential (voltage) from an injection of current. To measure the membrane potential, the MultiClamp 700B and Axoclamp 900A both monitor voltage drop initiated by current injection along an in-series resistor. Current-clamp is commonly used to inject simulated, but realistic current waveforms into a cell, and monitor membrane effect. This technique is ideal for the evaluation of important cellular events such as action potentials.
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Digital Acquisition
The current or voltage signal acquired by the amplifier is an analog signal, but to perform data analysis needed for high resolution patch-clamp measurements, the analog signal must be converted into a digital one. Positioned between the amplifier and the computer, the digitizer accomplishes this important task. Signal quality is extremely important and is impacted by the sampling frequency. The latest generation of Digidata digitizers sample at 500 kHz and can be equipped with HumSilencer, which eliminates 50/60 Hz line-frequency noise.
Digital Acquisition
The current or voltage signal acquired by the amplifier is an analog signal, but to perform data analysis needed for high resolution patch-clamp measurements, the analog signal must be converted into a digital one. Positioned between the amplifier and the computer, the digitizer accomplishes this important task. Signal quality is extremely important and is impacted by the sampling frequency. The latest generation of Digidata digitizers sample at 500 kHz and can be equipped with HumSilencer, which eliminates 50/60 Hz line-frequency noise.
Disease Research
Ion channels play a role in many diseases including hypertension, cardiac arrhythmias, gastrointestinal, immune and neuromuscular disorders, pathological pain, and cancer. By understanding the exact role that ion channel play in a particular disease, researchers might be able to find a way to affect the ion channel in such a way as to alter the course of the disease.
Disease Research
Ion channels play a role in many diseases including hypertension, cardiac arrhythmias, gastrointestinal, immune and neuromuscular disorders, pathological pain, and cancer. By understanding the exact role that ion channel play in a particular disease, researchers might be able to find a way to affect the ion channel in such a way as to alter the course of the disease.
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dSEVC
In discontinuous single-electrode voltage clamp (dSEVC), the tasks of voltage recording and current passing are allocated to the same micropipette.
dSEVC
In discontinuous single-electrode voltage clamp (dSEVC), the tasks of voltage recording and current passing are allocated to the same micropipette.
Electrophysiology
Electrophysiology is the field of research studying current or voltage changes across a cell membrane. Electrophysiology techniques are widely used across a diverse range of neuroscience and physiological applications; from understanding the behavior of single ion channels in a cell membrane, to whole-cell changes in the membrane potential of a cell, to larger scale changes in field potential within the brain slices in vitro or brain regions in vivo.
Electrophysiology
Electrophysiology is the field of research studying current or voltage changes across a cell membrane. Electrophysiology techniques are widely used across a diverse range of neuroscience and physiological applications; from understanding the behavior of single ion channels in a cell membrane, to whole-cell changes in the membrane potential of a cell, to larger scale changes in field potential within the brain slices in vitro or brain regions in vivo.
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Ion Channels
An ion channel is a group of proteins that form a pore across the lipid bilayer of a cell. Each channel is permeable to a specific ion (examples: potassium, sodium, calcium, chloride). Patch-clamp is used to evaluate current or voltage in the membrane associated with ion channel activity via direct measurement in real time using ultra-sensitive amplifiers, high-quality data acquisition systems, and powerful software to evaluate the results.
Ion Channels
An ion channel is a group of proteins that form a pore across the lipid bilayer of a cell. Each channel is permeable to a specific ion (examples: potassium, sodium, calcium, chloride). Patch-clamp is used to evaluate current or voltage in the membrane associated with ion channel activity via direct measurement in real time using ultra-sensitive amplifiers, high-quality data acquisition systems, and powerful software to evaluate the results.
Patch Clamp
The patch-clamp technique involves a glass micropipette forming a tight gigaohm (GΩ) seal with the cell membrane. The micropipette contains a wire bathed in an electrolytic solution to conduct ions. The whole-cell technique involves rupturing a patch of membrane with mild suction to provide low-resistance electrical access, allowing control of transmembrane voltage. Alternatively, investigators can pull a patch of membrane away from the cell and evaluate currents through single channels via the inside-out or outside-out patch-clamp technique.
Patch Clamp
The patch-clamp technique involves a glass micropipette forming a tight gigaohm (GΩ) seal with the cell membrane. The micropipette contains a wire bathed in an electrolytic solution to conduct ions. The whole-cell technique involves rupturing a patch of membrane with mild suction to provide low-resistance electrical access, allowing control of transmembrane voltage. Alternatively, investigators can pull a patch of membrane away from the cell and evaluate currents through single channels via the inside-out or outside-out patch-clamp technique.
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Series Resistance Compensation
Series resistance is the sum of all resistances between the amplifier and the inside of the cell using the whole-cell recording method. Due to Ohms Law, the larger this resistance, the greater the difference between the command level and the measured values. This creates an error in actual voltage or current measurement potentially leading to inaccurate observations. To overcome this, the Molecular Devices amplifiers have built-in circuitry to improve the bandwidth of the recording by compensating the error introduced by the voltage or current drop across the series resistance.
Series Resistance Compensation
Series resistance is the sum of all resistances between the amplifier and the inside of the cell using the whole-cell recording method. Due to Ohms Law, the larger this resistance, the greater the difference between the command level and the measured values. This creates an error in actual voltage or current measurement potentially leading to inaccurate observations. To overcome this, the Molecular Devices amplifiers have built-in circuitry to improve the bandwidth of the recording by compensating the error introduced by the voltage or current drop across the series resistance.
Single Channel Recording
The patch-clamp technique involves a glass micropipette forming a tight gigaohm seal with the cell membrane. The micropipette contains a wire bathed in an electrolytic solution to conduct ions. To measure single ion channels, a “patch” of membrane is pulled away from the cell after forming a gigaohm seal. If a single ion channel is within the patch, currents can be measured. The Axopatch 200B, with extremely low-noise profile, is ideal for this application, maximizing signal for the smallest conductance ion channels.
Single Channel Recording
The patch-clamp technique involves a glass micropipette forming a tight gigaohm seal with the cell membrane. The micropipette contains a wire bathed in an electrolytic solution to conduct ions. To measure single ion channels, a “patch” of membrane is pulled away from the cell after forming a gigaohm seal. If a single ion channel is within the patch, currents can be measured. The Axopatch 200B, with extremely low-noise profile, is ideal for this application, maximizing signal for the smallest conductance ion channels.
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The Axon Guide
A guide to Electrophysiology and Biophysics Laboratory Techniques. The purpose of this guide is to serve as an information and data resource for electrophysiologists. It covers a broad scope of topics ranging from the biological basis of bioelectricity and a description of the basic experimental setup to a discussion of mechanisms of noise and data analysis.
The Axon Guide
A guide to Electrophysiology and Biophysics Laboratory Techniques. The purpose of this guide is to serve as an information and data resource for electrophysiologists. It covers a broad scope of topics ranging from the biological basis of bioelectricity and a description of the basic experimental setup to a discussion of mechanisms of noise and data analysis.
Voltage Clamp Amplifier
In an experiment using the voltage-clamp method, the investigator controls the membrane voltage in a cell and measures the transmembrane current required to maintain that voltage. This voltage control is called a command voltage. To maintain this command voltage level, an amplifier must inject current. The current injected will be equal and opposite the current escaping through open ion channels, allowing the amplifier to measure the amount of current passing through open membrane bound ion channels.
Voltage Clamp Amplifier
In an experiment using the voltage-clamp method, the investigator controls the membrane voltage in a cell and measures the transmembrane current required to maintain that voltage. This voltage control is called a command voltage. To maintain this command voltage level, an amplifier must inject current. The current injected will be equal and opposite the current escaping through open ion channels, allowing the amplifier to measure the amount of current passing through open membrane bound ion channels.
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Whole Cell Recording
The whole cell patch-clamp technique involves a glass micropipette forming a tight gigaohm (GΩ) seal with the cell membrane. This micropipette contains a wire bathed in an electrolytic solution to conduct ions. A patch of membrane is subsequently ruptured by mild suction so that the glass micropipette provides a low-resistance access to the whole cell, thereby allowing the investigator to control the transmembrane voltage and allowing the investigator to evaluate the sum of all currents through membrane bound ion channels.
Whole Cell Recording
The whole cell patch-clamp technique involves a glass micropipette forming a tight gigaohm (GΩ) seal with the cell membrane. This micropipette contains a wire bathed in an electrolytic solution to conduct ions. A patch of membrane is subsequently ruptured by mild suction so that the glass micropipette provides a low-resistance access to the whole cell, thereby allowing the investigator to control the transmembrane voltage and allowing the investigator to evaluate the sum of all currents through membrane bound ion channels.
Latest Resources
Resources of Electrophysiology
Brochure
Axon™ Patch-Clamp
Axon™ Patch-Clamp
The Axon Instruments® portfolio provides comprehensive solutions for patch-clamping that includes amplifiers, digitizer, software, and accessories.
User Guide
The Axon™ Guide
The Axon™ Guide
The Axon Guide, a guide to electrophysiology and Biophysics laboratory techniques
Infographic
The Patch-Clamp Rig
The Patch-Clamp Rig
This guide provides information about the Patch-Clamp Rig. It is an important electrophysiology technique with a broad range of applications.
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