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BC-535 Preliminary, Rev. 060126
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Warner Instruments
1125 Dixwell Avenue, Hamden, CT 06514
(800) 599-4203 / (203) 776-0664
(203) 776-1278 - fax
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Table of Contents
Related Manuals for Warner Instruments BC-535
Summary of Contents for Warner Instruments BC-535
- Page 1 BC-535 Preliminary, Rev. 060126 Warner Instruments 1125 Dixwell Avenue, Hamden, CT 06514 (800) 599-4203 / (203) 776-0664 (203) 776-1278 - fax...
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Page 2: Table Of Contents
BC-535 Preliminary, Rev. 060126 NOMENCLATURE............................ 5 Text conventions ............................. 5 Device panel abbreviations ........................5 CONTROL DESCRIPTION........................6 Front panel .............................. 6 Hold..............................6 Offset ..............................7 Meter ..............................7 Outputs ..............................8 Capacitance compensation........................8 Power ..............................9 Rear panel ............................... 9 Headstage............................. - Page 3 BC-535 Preliminary, Rev. 060126 Perfusion ............................17 Oscilloscope ............................17 INITIAL TEST............................18 Amplifier setup ............................. 18 Overview..............................18 Initial conditions ........................... 18 Hold voltage test..........................19 Input noise test without model membrane ..................20 Input noise test with model membrane ....................20 Test instrument I output........................
- Page 4 Warner to present an instrument of broad capability and superior quality at a cost significantly below that of our competitors. The operational range of the BC-535 has been enhanced by the introduction of dual feedback- resistor circuitry within the headstage. This enhancement allows the amplifier to comfortably pass currents of up to 2 nA while preserving the sub-pA sensitivity of the instrument.
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Page 5: Nomenclature
BC-535 Preliminary, Rev. 060126 NOMENCLATURE Text conventions This manual refers to amplifier controls at three functional levels; control blocks, specific controls within a block, and settings of specific controls. To reduce confusion, we have employed several text conventions which are specified below. Since our goal is to provide clarity rather than complexity, we welcome any feedback you may wish to provide. -
Page 6: Control Description
BC-535 Preliminary, Rev. 060126 CONTROL DESCRIPTION The instrument front panel is divided into six control blocks titled HOLD OFFSET METER OUTPUTS , and . The instrument rear panel has BNC connectors for the CAP COMP POWER GAIN FILTER , and . -
Page 7: Offset
BC-535 Preliminary, Rev. 060126 Offset block contains the and the OFFSET INPUT OFFSET AUTO ZERO controls. section is comprised of a rotary potentiometer with INPUT OFFSET low/high LED’s, the pushbutton, the toggle, and an AUTO ZERO UNLOCK LED. This section is used to compensate for junction potentials ACTIVE produced by dissimilar solutions or other electrode potential differences. -
Page 8: Outputs
BC-535 Preliminary, Rev. 060126 Selection of ΣV displays the sum of all command voltages (V ) applied HOLD COMMAND INPUT to the headstage. The meter is capable of displaying command voltages up to ±1999 mV. The meter displays DC values and will average AC signals or pulses. -
Page 9: Power
CHASSIS GROUND plug. Therefore the instrument does not normally require a separate ground. However, it may become necessary to independently ground the chassis of the BC-535 when it is used as a freestanding device and not incorporated into a rack. -
Page 10: Gain Telegraph
BC-535 Preliminary, Rev. 060126 Note: We recommend separating the circuit and chassis grounds by disconnecting the bridging bar between the associated ground posts. Loosen the posts and slide the bridge to one side. Gain Telegraph is a stepped voltage output designed to communicate the instrument gain GAIN TELEGRAPH setting to your acquisition software. -
Page 11: Im Output
Capacitance output values are 1 mV/pF. Cap Sync Out This signal is used to synchronize an oscilloscope or other device with the BC-535 when using the function. The signal is keyed to the peak of the triangular wave for... -
Page 12: Model Membrane
BC-535 Preliminary, Rev. 060126 Model membrane The BC-535 is shipped with a model membrane, the MC-1, which can be used to test the performance of the amplifier. The MC-1 contains a 100 pF capacitor connected in parallel with a 1 GΩ... -
Page 13: Setup
These sources include exterior lighting, nearby instrumentation and electrical wiring. The cage can be fabricated from any conducting material and is grounded. While the design of the BC-535 facilitates Warner... -
Page 14: Vibration Isolation
An option exclusively presented by Warner Instruments consists of a Faraday cage with an enclosed vibration isolation table. This unique combination is specifically designed with the bilayer user in mind. -
Page 15: Amplification
Warner Instruments is the only manufacturer to produce a dedicated bilayer clamp amplifier, and it’s performance and feature set have been optimized for bilayer work. -
Page 16: Acquisition Hardware And Software
Warner Instruments provides a number of filtering devices which can be used in conjunction with the BC-535 to achieve a high degree of filter resolution. We recommend the use of a high quality 8-pole Bessel filter such as the LPF-8. -
Page 17: Perfusion
In general, fresh solution is added to the bottom of the recording chamber while the perfusate is removed from the top. Warner Instruments has developed the BPS-2, an easily assembled ‘traditional’ perfusion system, which integrates well with our Bilayer Workstation. -
Page 18: Initial Test
Therefore, before connecting the amplifier to the power source, check the serial number label on the rear of the amplifier for its voltage rating. Prior to turning on the BC-535 for the first time, verify that the line voltage is correct for the instrument. If the instrument voltage rating is incorrect for your area, contact our Service Department. -
Page 19: Hold Voltage Test
• time base to 5 ms/div • DC coupling on the input channel Turn on both the BC-535 and the oscilloscope. Hold voltage test • Connect the model membrane (MC-1) to the headstage inputs and the green wire from the model membrane to the headstage grounding jack. -
Page 20: Input Noise Test Without Model Membrane
BC-535 Preliminary, Rev. 060126 • Deactivate the by moving the toggle to the unlock position. The OFFSET CONTROLS UNLOCK LED will go off and the toggle will return to its original position. The offset reading on ACTIVE in the block will not change. -
Page 21: Test Instrument I Output
BC-535 Preliminary, Rev. 060126 • Switch the switch to operate. STANDBY OPERATE • You should observe a noise level of no greater than 6 mV p-p, equivalent to 0.171 pA RMS at this gain setting. • Place the amplifier into standby. -
Page 22: Capacity Compensation
BC-535 Preliminary, Rev. 060126 • Verify that the signal on the oscilloscope moved 1 div upwards. This corresponds to a 10 pA offset at this gain setting. • Depress the pushbutton. AUTO ZERO • LED will flash, indicating operation of the function. -
Page 23: Operation
BC-535 Preliminary, Rev. 060126 OPERATION The general procedure is to first set up the bilayer chamber, add solutions, and make electrical contact. This is followed by adjusting the input offset and forming the bilayer membrane. The strategy for incorporating channel containing membrane vesicles to the bilayer membrane will depend on the system under study, but will normally proceed by adding vesicles or purified protein to one side of the membrane under the appropriate ionic and/or osmotic conditions. -
Page 24: Input Offset
The BC-535 has an integral audio amplifier to aid in monitoring membrane formation. In general, there will be a dramatic drop in current as soon as lipid has filled the aperture and the audio signal will change accordingly. -
Page 25: Commands
BC-535 Preliminary, Rev. 060126 To observe the formation of a membrane, set the (in the block) to the off HOLD TOGGLE HOLD position, place the switch in the operate position, and turn the OPERATE STANDBY METER SELECTOR to cap test. Prior to membrane formation, and if the aperture is not occluded (with a bubble,... -
Page 26: Appendix
For either configuration, the ground for all external devices should be attached to a single external ground point. The BC-535 has two grounding posts on the rear of the instrument, one for and one for . The instrument is shipped with these two grounds... - Page 27 We recommend severing this connection and only using the CIRCUIT GROUND The schemes shown below and described above indicate connection of the BC-535 CHASSIS to an external ground point. However, it is often advantageous to try different ground GROUND configurations with the BC-535 to determine which works best in your environment.
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Page 28: Membrane Capacitance Calculations
BC-535 Preliminary, Rev. 060126 Membrane capacitance calculations It is possible to theoretically derive an equation to determine the size of the bilayer formed across the aperture. While this equation will probably not yield an exact result (most likely due to variation in the dielectric constant of your lipid mixture), it will give a reasonably approximate result. -
Page 29: Suggested References
It should be apparent from the preceding discussion that the magnitude of the current, and hence the amplitude of the resulting square wave, is linearly proportional to the area of the bilayer membrane. Since the amplifier output is scaled to 1 mV/pF when the BC-535 is in mode, application CAP TEST of the preceding discussion to the amplifier indicates that the measured capacitance of a membrane is simply the amplitude of the square wave (expressed in mV) divided by the instrument gain. -
Page 30: Specifications
BC-535 Preliminary, Rev. 060126 Specifications 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... - Page 31 BC-535 Preliminary, Rev. 060126 Specifications (continued) ± 1999 mV full scale Digital meter: 3.5 digit LED ± 120 mV full scale Junction offset: Cap Test: 0 to 1999 pF ± 1999 mV full scale ± 1999 pA full scale Power: 100-125 or 220-240 VAC, 50/60 Hz H ×...
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Page 32: Chloriding Electrodes
The BC-535 is shipped with two silver wires which must be chlorided prior to use. Over time, the AgCl coating on the wires will deteriorate. This will be most apparent as a gradual increase in the value of the junction potential seen at the beginning of each experiment. -
Page 33: Accessories And Replacement Parts
64-1327 Warranty The model BC-535 is covered by our Warranty to be free from defects in materials and workmanship for a period of three years from the date of shipment. If a failure occurs within this period, we will either repair or replace the faulty component(s). This warranty does not cover instrument failure or damage caused by physical abuse or electrical stress (inputs exceeding specified limits). - Page 34 BC-535 Preliminary, Rev. 060126 2. Occasionally, a knob on the front panel will loosen after long use. These are "collet" style knobs and are tightened with a screw located under the knob cap. To gain access to the adjustment screw, pry the cap off with a thin bladed screwdriver or similar tool.
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Page 35: Certifications
BC-535 Preliminary, Rev. 060126 Certifications Declaration of Conformity CE MARKING (EMC) Application of Council Directive: 89/336/EEC Standards To Which Conformity EN55022 Class A Is Declared: EN61000-3-2 EN61000-3-3 EN50082-1:1992 EN61000-4-2 EN61000-4-3 ENV50204 EN610000-4-4 EN610000-4-8 EN610000-4-11 Manufacturer’s Name: Warner Instruments Manufacturer’s Address:... - Page 36 BC-535 Preliminary, Rev. 060126 Declaration of Conformity CE MARKING (LVD) Application of Council Directive: 73/23/EEC Standards To Which Conformity Is EN61010-1:1993 Declared: Manufacturer’s Name: Warner Instruments Manufacturer’s Address: 1125 Dixwell Avenue Hamden, CT 06514 Tel: (203) 776-0664 Instrument Amplifier Equipment Description:...
- Page 37 BC-535 Preliminary, Rev. 060126 BC-535 Preliminary, Rev. 060126 Warner Warner Instruments Instruments A Harvard Apparatus Company A Harvard Apparatus Company...
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Page 38: Glossary
BC-535 Preliminary, Rev. 060126 Glossary A/D converter – Analog to Digital converter. Computers are inherently digital while the voltage or current output from an amplifier is analog. Therefore, a signal must be first converted to a digitized form before a computer or its software can accept it. Desirable features in an A/D converter include rapid signal conversion, small-step resolution and low noise. - Page 39 BC-535 Preliminary, Rev. 060126 – Also . Command Input. An external input into the BC-535 allowing the application of COMMAND IN CMD IN user defined command voltages to the headstage. Connection is via BNC. command sensitivity – Selectable scaling of input.
- Page 40 BC-535 Preliminary, Rev. 060126 ground loop – A loop formed from multiple connections into the circuit ground plane by the same device. The flux of magnetic fields through this loop can induce small currents within the ground plane resulting in increased noise in the circuit. Careful consideration of the interconnection between several devices is often required to identify ground loops.
- Page 41 BC-535 Preliminary, Rev. 060126 reset – An operation wherein the collected charge on the integrating capacitor in the headstage is dissipated, readying the system for further use. signal polarity – Defined as the sign applied to a current generated through a membrane in the presence of an applied holding potential.
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