Specialized Tools for Electrophysiology and Cell Biology Research

(BC-535) Bilayer Clamp Amplifier

Product Summary

The BC-535 is the newest version of our popular bilayer clamp amplifier. Warner Instruments is the manufacturer dedicated to supplying an instrument specifically designed for research using planar lipid bilayer technology, and this device forms an integral component of the BLM Workstation.


  • Resistive feedback headstage - no reset glitch!
  • Reduced noise and wider bandwidth
  • Improved stability with gains to 1000 mV/pA
  • Digital hold potential
  • AutoZero function
  • Digital readout of membrane capacitance
  • Multi-step 4-pole Bessel filter
  • Hold potentials to 1400 mV; currents to 20 nA

Resistive Feedback Headstage

BC-535 has an advanced, dual-resistive feedback headstage which provides high bandwidth and low noise recording. The switchable headstage resistance is automatically selected based on the gain setting. A low current mode provides up to 100 pA of current carrying capability, while the high current mode provides up to 20 nA of current capacity!

Hold Control

The hold control for the BC-535 has been redesigned to function entirely within the digital domain. This unique approach allows the user to make holding potential adjustments in highly reproducible and discrete steps of 1 and 10 mV, up to ±400 mV. Hold potentials up to ±1000 mV or step sizes greater than 10 mV can be applied at the Command Input BNC.s located on the front and rear panels of the instrument.


The large currents flowing through the low resistance aperture prior to membrane formation saturates the amplifier input. Under these conditions, junction potential offsets can be easily nullified by using the AutoZero function. Once armed, the AutoZero cycle measures and compensates for any offset potentials in the conducting pathway. Traditional manual controls remain for making small corrections or for resetting the offset potential without reactivating the AutoZero cycle.

Audio Output

The BC-535 sports a VCO circuit providing auditory feedback during membrane formation. An internal speaker is included and an external speaker output is provided on the instrument rear panel.

Bilayer Clamp Amplifier (BC-535)

Capacitance Test

This test circuit has been completely redesigned and is used to monitor the formation of the bilayer membrane. A triangle waveform is applied to the command input and the amplitude of the resulting square wave is proportional to the membrane capacitance. When selected, the membrane capacitance is read directly from the meter.

4-Pole Bessel Filter

The filtering capacity if the instrument has been expanded to include a low pass, 4-pole Bessel filter ranging from 0.05 to 20 kHz in 1-2-5 steps. The internal filter can be bypassed for use with external filtering apparatus and allows realization of the instrument's full 75 kHz bandwidth.

Capacitance Compensation

Large capacitance transients are cancelled using both fast (0-10 us) and slow (0.2 ms) controls. Each control provides separate adjustment of both amplitude and time constant. Maximum capacitance compensation is 500 pF.


Input and output BNCs have been duplicated or moved to the instrument rear panel except for those requiring user interaction. Front panel BNCs include Command Input, Vcx10 and Im Output. Rear panel BNCs include the headstage connecter, Im Output, Cap Sync, Cap Out, Command In, Gain and Filter telegraphs, and a speaker output.

Noise Measured with 8 pole Bessel filter at specified cutoff frequency
Frequency Range Open Input 100 pF at Input
DC to 1 kHz 0.060 pA RMS 0.82 pA RMS
DC to 100 Hz 0.009 pA RMS 0.28 pA RMS
Bandwidth 75 kHz
Input Commands Hold Digital; 1 or 10 mV steps to ±400 mV maximum
Command In Front and rear external input, 10 V/V (applied voltage is attenuated by 10/100/1000 at the command electrode)
Junction Zero AutoZero or manual adjust. AutoZero lockout feature. Cycle time 1.5 s, correction to ±120 mV
Audio VCO with off switch and volume control, Internal speaker and external speaker output
Capacitance Test Triangle wave applied to command electrode; derived membrane capacitance read from meter up to 1000 pF; calibrated (1 mV/pF) square wave available at Im output; Cap Sync (rear panel) synchronized with input triangle wave
Gain Membrane current gain selectable from 0.5 to 1000 mV/pA in 1-2-5 steps
Filter 4-pole Bessel selectable from 0.05 to 20 kHz in 1-2-5 steps, or bypassed for full amplifier bandwidth
Capacity Compensation Fast (0-10 µs) and slow (0-2 ms) with adjustment of amplitude and time constant for each range. Maximum compensation 500 pF
Headstage Switching
Low Current Mode 50 gigohm feedback, 100 pA maximum current
High Current Mode 500 megohm feedback, 20 nA maximum current
Front panel
Command Input BNC input up to 10V. Attenuated by 10, 100 or 1000
Im Output Membrane current scaled by amplifier gain setting
Vc x 10 Output Applied command voltage x10
Rear panel
Im Output Membrane current scaled by amplifier gain setting.
Cap Sync TTL compatible
Capacitance output Reports calculated membrane capacitance scaled to 1 mV/pF
Command Input BNC input up to 10V. Attenuated by 10, 100 or 1000.
Gain Telegraph Stepped DC voltage 0.5 to 5.5 V in 0.5 V steps for gain settings of 0.5 to 1000 mV/pA. Telegraph value of 0 V for bypass mode.
Filter Telegraph Stepped DC voltage 0.5 to 4.5 V in 0.5 V steps for filter settings of 0.05 to 20 kHz. Telegraph value of 5.0 V for full bandwidth (bypass) mode.
External speaker Standard RCA jack
Digital Meter 3.5 digit LED ±1999 mV full scale
Junction offset ±120 mV full scale
Cap Test 0 to 1999 pF
Vc ±1999 mV full scale
Im ± 1999 pA full scale
Warranty 3 years parts and labor
Power 100-125 or 220-240 VAC, 50/60 Hz, 20 VA
H x W x D
Case 9 x 42 x 25 cm (3.5 x 16.5 x 10 in)
Headstage 2.3 x 2.8 x 5.8 cm (0.9 x 1.1 x 2.25 in)
1.8 m connecting cable

Rear View

Bilayer Clamp Amplifier (BC-535)

Click to Enlarge

Order No. Model No. Product Description USA Price Order
64-1327 WA10-5 Silver wire, 10 cm long, 0.25 mm dia, with 1 mm pin, 2 pack Login Login
64-1644 BMC-1 Bilayer model membrane Login Login
64-0435 HST-1 Headstage holder system for bilayer Login Login


  1. Pxmp2 Is a Channel-Forming Protein in Mammalian Peroxisomal Membrane 
    Rokka A, Antonenkov VD, Soininen R, Immonen HL, Pirilä PL, Bergmann U, Sormunen RT, Weckström M, Benz R, Hiltunen JK 
    PLoS One. 2009;4(4):e5090. Epub 2009 Apr 7
  2. Structure and Function of Colicin S4, a Colicin with a Duplicated Receptor-binding Domain 
    Arnold T, Zeth K, Linke D 
    J Biol Chem. 2009 Mar 6;284(10):6403-13. Epub 2008 Dec 4
  3. Preventing Voltage-dependent Gating of Anthrax Toxin Channels Using Engineered Disulfides 
    Anderson DS, Blaustein RO 
    J Gen Physiol. 2008 Sep;132(3):351-60
  4. Nucleotide Identification and Orientation Discrimination of DNA Homopolymers Immobilized in a Protein Nanopore 
    Purnell RF, Mehta KK, Schmidt JJ 
    Nano Lett. 2008 Sep;8(9):3029-34. Epub 2008 Aug 13
  5. BLM Analyzer: a software tool for experiments on planar lipid bilayers. 
    Novák P, Gaburjáková M, Zahradník I 
    Biotechniques. 2007 Mar;42(3):335-6, 338-9, 341
  6. Ryanodine receptor/calcium release channel PKA phosphorylation: A critical mediator of heart failure progression 
    Wehrens XH, Lehnart SE, Reiken S, Vest JA, Wronska A, Marks AR 
    Proc Natl Acad Sci U S A. 2006 Jan 17;103(3):511-8. Epub 2006 Jan 6
  7. A loop network within the anthrax toxin pore positions the phenylalanine clamp in an active conformation 
    Melnyk RA, Collier RJ 
    Proc Natl Acad Sci U S A. 2006 Jun 27;103(26):9802-7. Epub 2006 Jun 19
  8. Enhancing calstabin binding to ryanodine receptors improves cardiac and skeletal muscle function in heart failure 
    Wehrens XH, Lehnart SE, Reiken S, van der Nagel R, Morales R, Sun J, Cheng Z, Deng SX, de Windt LJ, Landry DW, Marks AR 
    Proc Natl Acad Sci U S A. 2005 Jul 5;102(27):9607-12. Epub 2005 Jun 22





Customers from Europe and Australia can use the Multi Channel Systems - Online Shop to order Warner products or create quotes.

Order No. Model No. Product Description USA Price Order
64-0432 BC-535 Bilayer clamp amplifier with resistive headstage Login Login
460-7013 BNC-6 BNC to BNC cable, 6 feet (Pomona) Login Login
460-7032 BNC-2 BNC to BNC cable, 2 feet (Pomona) Login Login
64-0435 HST-1 Headstage holder system for bilayer Login Login
64-0454 BNA48 Ground cable, banana-banana, 48" Login Login
Replacement Parts
64-1327 WA10-5 Silver wire, 10 cm long, 0.25 mm dia, with 1 mm pin, 2 pack Login Login
64-1644 BMC-1 Bilayer model membrane Login Login
460-8090 2U Rack handle Login Login

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