A computer-controlled amplifier for current-clamp and voltage-clamp applications
The MultiClamp™ 700B Microelectrode Amplifier from Molecular Devices is a computer-controlled microelectrode current- and voltage-clamp amplifier for electrophysiology and electrochemistry. This versatile amplifier is capable of singlechannel and whole-cell voltage patch-clamp,high-speed current-clamp (sharp electrode or field potentials), ion-selective electrode recording,amperometry/voltammetry and bilayer recordings.
The MultiClamp 700B amplifier is designed to support up to two primary CV-7B headstages and two optional auxiliary (HS-2 or VG-2 type) headstages.
Each CV-7B headstage contains a currentto-voltage converter for voltage-clamp and a voltage follower for true current-clamp.This allows the user to conveniently switch between low-noise patch-clamp recording and high-speed current-clamp recording. An optional CV-7B/BL headstage is available for bilayer recording.
True current-clamp and voltage-clamp headstage
Traditionally, amplifiers are designed for optimal performance in voltage-clamp or current-clamp mode, but cannot perform both during the same experiment. The CV-7B headstages supplied with the MultiClamp 700B amplifier overcome this limitation by integrating both current-to-voltage and voltage-following circuitry. This design allows users to rapidly switch between patch-clamp recording and high-speed current-clamp recording. The CV-7B headstage has four different feedback resistors in voltage-clamp mode, allowing for a wide range of cellular recording. In current-clamp mode, the CV-7B headstage provides three different current setting resistors to clamp current from a few pA up to 200 nA.With two headstages, the MultiClamp 700B amplifier can perform the function of two patch-clamp, two current-clamp, or a combination of patch- and current-clamp amplifiers. In addition, two optional voltagefollower headstages (HS-2 type) can be connected to auxiliary inputs to allow third- and fourth-point voltage recording. Dual headstages allow more complex synaptic experiments to be performed, as well as increasing throughput for drug discovery experiments, all at a significantly
lower cost per channel.Specialized headstages are available for bilayer and electrochemistry recordings. The optional CV-7B/BL headstage was designed to handle the large membrane capacitances found in bilayer recording. The CV-7B/EC headstage was designed to handle the large (±2V)command voltages required during electrochemistry recording.
Computer control
MultiClamp 700B Commander Software The MultiClamp 700B amplifier is fully controlled by the MultiClamp Commander software. Computer control allows for tremendous flexibility, including broad ranges of current passing and recording levels, extensive filtering options and multiple signal outputs.
Computer control simplifies the patching process by providing automation of pipette offset, fast/slow electrode capacitance compensation, whole-cell capacitance compensation, series resistance correction, pipette capacitance neutralization and bridge balance—all without moving parts.