Axoclamp 900A Amplifier

For two-electrode voltage clamp recordings, whole-cell current-clamp recordings, intracellular sharp electrode recordings, extracellular field potential recordings in ion channel, neuroscience, oocyte and iontophoresis studies

Axoclamp 900A Microelectrode Amplifier is a complete microelectrode current clamp and voltage clamp amplifier, useful for a wide range of intracellular microelectrode recording techniques.

This amplifier features many enhancements that improve its recording capability, make the amplifier easier to use, and your experiments last longer. The Axoclamp 900A Microelectrode Amplifier provides the following modes of operation:
I-Clamp: Current clamp using two independent bridge amplifiers for voltage measurements
DCC: Discontinuous current clamp for accurate voltage measurements, even when the electrode resistance changes
TEVC: High-compliance two-electrode voltage clamp for Xenopus oocytes and mammalian cells
dSEVC: Discontinuous single-electrode voltage clamp for small cells with large currents
HVIC: High-voltage current clamp for extracellular applications such as iontophoresis
  • Five modes of operation provide the broadest range of electrophysiological applications
  • Software control of all amplifier settings for automated optimization features, reduction of manipulation steps, and convenient, reliable telegraphing
  • Optional SoftPanel allows amplifier control using knobs and buttons for a more conventional feel to amplifier control
  • Large output compliance range (±180 V in TEVC and HVIC modes) enables passing larger currents and ensures faster clamp speeds
  • Wide AC voltage clamp gain ranges in TEVC and dSEVC modes for excellent voltage control
  • Space-saving headstage design for easier access to the preparation on a crowded microscope stage
  • New dSEVC design with more stability and faster clamp provides an excellent alternative to standard continuous single-electrode voltage clamping
  • Pipette Capacitance Compensation neutralizes the contribution of the glass pipette and the pipette holder to the capacitance of the circuitry
  • Automatic oscillation detection prevents damage to a cell when electrical feedback occurs
  • Selectable output gain with 11 settings to scale the output signal to the desired level
  • Audio monitor for acoustic tracking of the signal while you are busy looking down a microscope
  • Fine-tunable 4-pole Bessel and Butterworth low-pass filters act as anti-aliasing filters and can be used to pre-condition the output signal
  • Buzz feature with a hand-held remote switch facilitates breaking through cell membranes
  • Two included pipette holders of different barrel lengths accept glass pipettes in most standard dimensions
  • User guide written by scientific consultants, with the assistance of Axon Instruments staff, for straightforward start-up and as an in-depth reference

Basic Ion Channel Research

Ion channels are pore proteins that are involved in a large variety of physiological processes. Basic research in the ion channel field furthers the understanding of ion channel function as well as their roles within cellular pathways and processes. Single-channel research helps with elucidating the mechanisms underlying ion channel function on a single-molecule level. Whole-cell and perforated patch clamp recordings are typically used to investigate the action of modulators on entire populations of ion channels in the membrane of a cell. Learn more.

Cell 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, neuronal communications, etc. Learn more.

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 channels 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. Learn more.

Safety Assessment

A critical part of drug discovery involves safety assessments, such as hERG testing, in order to eliminate any compounds with potential safety concerns. Conventional patch clamp has played an important role in collecting evidence for the absence of side effects before submission of a drug candidate to regulatory authorities. Even if automated electrophysiology has shifted safety testing to earlier stages in the drug discovery process, follow-up with conventional patch clamp is an essential step in the workflow. Learn more.

AxoClamp Commander SoftwareAxoclamp Commander Software

Instead of the traditional front panel knobs and switches, the Axoclamp 900A Amplifier is controlled by the Axoclamp 900A Commander Software, a program that runs on a Windows PC computer (see system requirements) and communicates with the amplifier via a USB interface. This control interface reports resistance, voltage, and current measurements and provides automation of Bridge Balance, Pipette Offset, and Pipette Capacitance Neutralization for improved ease of use. In addition, Axoclamp Commander has "smart" features that protect cells from potentially damaging signal oscillations and automate mode changes based on internal signal thresholds or externally applied signals. Amplifier settings such as gain, filter frequency, recording mode, and input/output scale factors are automatically telegraphed to the pCLAMP 10 Data Acquisition Software via the USB connection.  This ensures that the amplifier settings are accurately and conveniently stored in the recorded data files.

To obtain the installer for a more in-depth look at Axoclamp 900A Commander Software, please go to our Customer Support page.

In combination with a Digidata 1550B Data Acquisition System and pCLAMP Software, the Axoclamp 900A Amplifier forms the core of a recording setup like those used in many electrophysiology labs around the world.  Computer control of the amplifier ensures correct scaling and logging of experimental parameters. The Clampex Data Acquisition Module in pCLAMP Software makes optimal use of the features of the Axoclamp 900A Amplifier.

General Specifications

General Specifications
Dimensions (in.) 4.3 (H) x 19 (W) x 14.3 (D)
Dimensions (cm) 10.9 (H) x 48.3 (W) x 36.3 (D)
Weight 9.5 lbs. (4.3 kg)
Headstage (in.) 0.75 (H) x 0.70 (W) x 2.25 (D)
Headstage (cm) 1.9 (H) x 1.8 (W) x 5.7 (D)
Rack use Bayonet feet

100-240 VAC 50-60 Hz,

30 W max
Safety CE marking (Conformité Européenne)

Detail Specifications


Axoclamp 900A Headstages
Maximum Current*            
Headstage Ro (Ch1 &2) (Ch2) (Ch2) (Ch1) (Ch1)
HS-9Ax0.1U 100M 0.12μA 1.8μA 1.8μA 0.036μA 0.036μA
10M 1.20μA 18.0μA 18.0μA 0.360μA 0.360μA
HS-9Ax10U 1M 12.00μA 180.0μA 180.0μA 3.600μA 3.600μA

*Maximum current specifications assume negligible electrode resistance.

Axoclamp 900A Headstages
Description Details Part Number
Axoclamp 900A Headstage HS-9A X0.1U x0.1 headstage 1-2950-0359
Axoclamp 900A Headstage HS-9A X1U x1 headstage 1-2950-0360
Axoclamp 900A Headstage HS-9A X10U x10 headstage 1-2950-0361
Axoclamp 900A Headstage VG-9A X10U x10 virtual ground headstage 1-2950-0362
Axoclamp 900A Headstage VG-9A X100U x100 virtual ground headstage 1-2950-0363

SoftPanel Interface


To offer a more conventional interface to amplifier control, the optional SoftPanel was designed as a hardware extension to replicate all essential amplifier functions by acting as a hardware extension to the Axoclamp and MultiClamp Commander Software. The SoftPanel controller communicates with the computer via an easy-to-set up USB 2.0 connection. Using the SoftPanel knobs replicate continuous mouse controls ("gliders"), while buttons replicate single-click mouse controls without negating the many benefits afforded by computer control of the amplifier.

The Axoclamp 900A Amplifier is compatible with the following products.


Description Details Part Number
Axoclamp 900A Headstage HS-9A X0.1U x0.1 headstage 1-2950-0359
Axoclamp 900A Headstage HS-9A X1U x1 headstage 1-2950-0360
Axoclamp 900A Headstage HS-9A X10U x10 headstage 1-2950-0361
Axoclamp 900A Headstage VG-9A X10U x10 virtual ground headstage 1-2950-0362
Axoclamp 900A Headstage VG-9A X100U x100 virtual ground headstage 1-2950-0363
MultiClamp 700B Headstage CV-7B Patch-clamp headstage 1-CV-7B
MultiClamp 700B Headstage CV-7B/BL Bilayer headstage 1-CV-7B/BL
MultiClamp 700B Headstage CV-7B/EC Electrochemistry headstage 1-CV-7B/EC

Electrode holders, adapters, and holder components

Description Details Part Number
Electrode Holder for U-Type Headstages Fits glass pipettes with outer diameter of 1.0 - 1.7 mm 1-HL-U
Electrode Holder Replacement Caps Set of 2 polycarbonate caps for HL-U holders 1-HL-CAP
Cone Washers 1.1mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.0 - 1.1 mm 1-HLC-11
Cone Washers 1.3mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.1 - 1.3 mm 1-HLC-13
Cone Washers 1.5mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.3 - 1.5 mm 1-HLC-15
Cone Washers 1.7mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.5 - 1.7 mm 1-HLC-17
Pins 1mm for HL-U Holders Set of 3 brass pins for HL-U holders, 1mm 1-HLP-U
2mm Plugs with Solder Cups Set of 5 general purpose gold plugs, 2mm, with solder cups 1-HLP-0
Silver Wire Set of 5 Ag wires, 0.25mm diameter, 50mm long 1-HLA-005
Silicone Tubing for Silver Wire 1mm ID x 70mm Long Silicone Tubing 1-HLT-70
Silver/Silver Chloride Pellet Assemblies Set of 3 Ag/AgCl pellet assemblies 1-HLA-003
Adapter For BNC Holders To U-Type Headstages Connects BNC holders to CV and HS headstages with threaded collets (U-type) 1-HLB-U
Right-Angle Adapter for HL-U Electrode Holders Fits CV and HS headstages with threaded collets (U-type) 1-HLR-U

Model Cells

Description Details Part Number
Model Cell for Oocytes Axoclamp/ GeneClamp model cell for oocytes. Connects to U-type HS series headstages 1-MCO-2U
Model Cell for TEVC / DSEVC Axoclamp/ GeneClamp model cell for two-electrode voltage clamp/ discontinuous single-electrode voltage-clamp conditions. Connects to U-type HS series headstages 1-CLAMP-1U
Model Cell for Whole Cell/ Single Channels Axopatch/ GeneClamp/ MultiClamp model cell for whole-cell / single-channel patch-clamp conditions. Connects to U-type CV series headstages 1-PATCH-1U
Model Cell for Bilayers Axopatch/ GeneClamp/ MultiClamp model cell for bilayer conditions. Connects to U-type CV series headstages 1-MCB-1U


Description Details Part Number
Cable To Connect Axoclamp 2 Headstages To Axoclamp 900A Amplifier Allows Axoclamp 2 headstages (HS-2, VG-2) to be used on Axoclamp 900A Amplifiers 1-2100-0934


Description Details Part Number
SoftPanel Amplifier Control Unit Provides physical knob and button control for computer-controlled Axoclamp 900-series and MultiClamp 700-series amplifiers. Requires a USB connection. 1-SOFTPANEL (USB)
Remote Buzz For Axoclamp 900A Hand-held buzz duration control for Axoclamp 900A Amplifier (1-50ms) 1-2950-0366
Silver/Silver Chloride Pellet Assemblies Set of 3 Ag/AgCl pellet assembly and Ag wire 1-HLA-003

Number of Citations*: 261

Latest Citations:

For a complete list of citations, please click here.


The Neurexin-NSF interaction regulates short-term synaptic depression

T Li, Y Tan, Q Li, H Chen, H Lv, W Xie, J Han - Journal of Biological …, 2015 - ASBMB
... Two-electrode voltage-clamp recordings were performed with an Axoclamp 900A
amplifier (Molecular Devices, Sunnyvale, CA, USA) using both recording (15-20MΩ)
and current-passing (5-8MΩ) electrodes filled with 3M KCl. ...

Functional Impact of 14 Single Nucleotide Polymorphisms Causing Missense Mutations of Human α7 Nicotinic Receptor

Q Zhang, Y Du, J Zhang, X Xu, F Xue, C Guo, Y Huang… - PloS one, 2015 -
... The chamber was grounded through an agar KCl bridge. The oocytes were
voltage-clamped at-70 mV to measure ACh-, nicotine-, or 4BP-TQS-induced currents using
an AxoClamp 900A amplifier (Molecular Devices, Sunnyvale, CA, USA). ...

Feedback in the brainstem: An excitatory disynaptic pathway for control of whisking

DW Matthews, M Deschênes, T Furuta… - Journal of …, 2015 - Wiley Online Library
... cases (8 of 15), vibrissa-responsive neurons in Vg were located by manual mechanical stimulation
of the ipsilateral vibrissae while extracellular recording in Vg with a thin tip diameter (∼10 μm)
quartz pipette filled with 0.5 M NaCl, amplified (Axoclamp 900A; Molecular Devices ...

Decline in the Recovery from Synaptic Depression in Heavier Aplysia Results from Decreased Serotonin-Induced Novel PKC Activation

TW DunnWS Sossin - PloS one, 2015 -
... Sharp glass electrodes 15–25MΩ backfilled with 2M potassium acetate, were manipulated to
the cells with Sutter MP-225 micromanipulators (Sutter Instruments) and membrane potentials
amplified with an Axoclamp 900A with signals digitized using a Digidata 1440A and ...

Functional roles of clusters of hydrophobic and polar residues in the epithelial Na+ channel knuckle domain

J Chen, EC Ray, ME Yates, TM Buck, JL Brodsky… - Journal of Biological …, 2015 - ASBMB
... at 7.4. Voltage clamp was performed using an Axoclamp 900A computer-controlled
microelectrode amplifier and DigiData 1440A interface controlled by pClamp version
9.2 (Molecular Devices Corp., Sunnyvale, CA). The protocol ...

Diabetes Affects the Temporal Dynamics of the Repolarization Properties of Cardiomyocytes

O MesteM MeoS Signore… - Computing in …, 2015 -
... Isolated cardiomyocytes were placed in a bath of Tyrode solution on the stage of an IX53 (Olympus)
microscope for whole-cell patch-clamp mea- surements. APs were measured in current-clamped
my- ocytes through an Axoclamp 900A amplifier (Molecular Devices). ...

Gene Dosage in the Dysbindin Schizophrenia Susceptibility Network Differentially Affect Synaptic Function and Plasticity

AP Mullin, MK Sadanandappa, W Ma… - The Journal of …, 2015 - Soc Neuroscience
... For all electrophysiological experiments, a magnetic glass microelectrode horizontal puller
(PN-30; Narishige) was used to prepare microelectrodes (30–70 MΩ resistance, backfilled with
3M KCl). Amplification of signals was achieved using Axoclamp 900A...

Impact of basal forebrain cholinergic inputs on basolateral amygdala neurons

CT Unal, D Pare, L Zaborszky - The Journal of Neuroscience, 2015 - Soc Neuroscience
... In contrast, in whole-cell mode, Alexa 594 diffused throughout the cells during the recordings.
Current- and voltage-clamp recordings were obtained with an Axoclamp 900A amplifier and
digitized at 10 kHz with a Digidata 1440A interface (Molecular Devices). ...

Somatostatin 2A receptors are not expressed on functionally identified respiratory neurons in the ventral respiratory column of the rat

S Le, AJ TurnerLM Parker, PG Burke… - Journal of …, 2015 - Wiley Online Library
... (3000 MW, Invitrogen # D3307) or 2% neurobiotin (tip diameter, 1 µm, resistance 10-25 M ).
Extracellular recordings were amplified (Axoclamp 900A, Molecular Devices) and simultaneously
captured on two channels using differing filter sets, one configured for ...

Murine and human CFTR exhibit different sensitivities to CFTR potentiators

G Cui, NA McCarty - … Journal of Physiology-Lung Cellular and …, 2015 - Am Physiological Soc
... Currents were acquired with an Axoclamp 900A amplifier and Clampex 10.2 software, and current
data were digitized at 2 kHz. Fractional change of current (F c ) at steady-state in response to
exposure to chemicals was calculated according to the equation. ...


* as of November 13, 2015. Source: Google Scholar.  Search results include "Axoclamp 900A" and "Axoclamp Axon Instruments".