Warner Instruments BC-535 Скачать руководство пользователя страница 13 | Manualshive

Страница: 13 / 41

Warner Instruments BC-535 Скачать руководство пользователя страница 13

BC-535 Preliminary, Rev. 060126

13

SETUP

For those with little experience in bilayer work, we suggest a review of Ion Channel

Reconstitution edited by C. Miller, Plenum Press, New York, 1986. In particular, Chapter 5, "How To
Set Up A Bilayer System", covers many important aspects of the subject. Several other pertinent
references are included in the appendix at the back of this manual.

Figure 1. Schematic representation of a BLM setup.

Basic design

A planar lipid bilayer (BLM) workstation, used to record currents through actively gating, ion

conducting single channels, is a complex apparatus requiring several components working in concert.
These components include a means to support the lipid membrane, high gain amplification, shielding
of electromagnetic interference, shielding of mechanical vibration, mechanisms for stirring and
changing solutions, signal filtering, data acquisition analysis, and a means to archive acquired data.

A schematic representation of a basic BLM layout is shown in Figure 1. Warner Instruments

provides all components used in the assembly of a BLM workstation, including Faraday cages,
vibration isolation tables, a dedicated bilayer clamp amplifier, high quality signal filtering devices,
illumination and stirring mechanisms, cups and chambers, and perfusion apparatus.

The components listed above may be assembled in various ways to achieve a working system.

Regardless of the configuration used, care must be taken in the design of a BLM workstation to
minimize both mechanical and electrical noise sources since single channel currents are often only a
few pA in magnitude. In this section we describe the basic design of a BLM workstation.

Faraday cage

A Faraday cage is an enclosure designed to shield the sensitive electronics in the headstage from

electromagnetic interference generated by noise sources in the vicinity of the apparatus. 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

Instruments

A Harvard Apparatus Company .

«
...
11
12
13
14
15
...
»

Содержание BC-535

Страница 1: ...ne er r I In ns st tr ru um me en nt ts s B Bi il la ay ye er r C Cl la am mp p A Am mp pl li if fi ie er r M Mo od de el l B BC C 5 53 35 5 Warner Instruments 1125 Dixwell Avenue Hamden CT 06514 800...

Страница 2: ...r panel 9 Headstage 9 Circuit and chassis grounds 9 Gain Telegraph 10 Filter Telegraph 10 Im output 11 External Command In 11 Capacitance Output 11 Cap Sync Out 11 External speaker 11 ADDITIONAL INFOR...

Страница 3: ...ozero 21 Capacity compensation 22 OPERATION 23 Setup of the bilayer chamber 23 Input offset 24 Input offset adjustment 24 Bilayer formation 24 Commands 25 APPENDIX 26 Theoretical considerations 26 Shi...

Страница 4: ...nge of the digital hold control has been extended to 400 mV for internally generated commands and the amplifier supports up to 1 V at the external command input for a sum capability of 1400 mV hold po...

Страница 5: ...MALL CAPS References to specific controls within a block are specified using NON UNDERLINED SMALL CAPS Finally references to individual control settings are specified in italic type Special comments a...

Страница 6: ...ential The maximum range for this control is 400 mV The internally generated HOLD command can be disabled by selecting the off position on the ON OFF TOGGLE SWITCH to the right of the meter Note The M...

Страница 7: ...tment is only available when the offset circuit is armed Fine adjustment of the rotary control can be achieved by pressing the control in while turning Low high LED s are provided to indicate which di...

Страница 8: ...FILTER TELEGRAPH BNC on the instrument rear panel The AUDIO section is comprised of an on off toggle and volume control Audio output is useful during membrane formation to monitor the successful appl...

Страница 9: ...ops Circuit and chassis grounds CIRCUIT and CHASSIS GROUND binding posts are provided at the rear of the amplifier to allow modification of instrument grounding The CHASSIS GROUND binding post is inte...

Страница 10: ...d below Im GAIN settings are selectable in the front panel OUTPUTS block see page 8 Im Gain mV pA Gain Telegraph V standby 0 0 0 5 0 5 1 1 0 2 1 5 5 2 0 10 2 5 20 3 0 50 3 5 100 4 0 200 4 5 500 5 0 10...

Страница 11: ...f the resulting square wave The SYNC OUT signal is a standard TTL square wave and is 100 s in duration External speaker A standard RCA jack is provided for attachment to an external speaker for use in...

Страница 12: ...mplifier The MC 1 contains a 100 pF capacitor connected in parallel with a 1 G resistor The precision of this resistor is 5 The MC 1 connects to the two 1 mm mini jacks on the headstage marked INPUT a...

Страница 13: ...a basic BLM layout is shown in Figure 1 Warner Instruments provides all components used in the assembly of a BLM workstation including Faraday cages vibration isolation tables a dedicated bilayer clam...

Страница 14: ...cal noise is critical to increasing the signal to noise ratio of a BLM workstation The significance of this becomes apparent when one considers that the acoustic coupling of normal speech to the buffe...

Страница 15: ...gn employed by Warner cups Another aperture geometry commonly used is that of a conical hole with the small end of the hole supporting the bilayer membrane This geometry often employed on custom made...

Страница 16: ...ata has been acquired and stored it must be analyzed for its biophysical characteristics Since the volume of data collected is often exceedingly large analysis is usually performed by dedicated softwa...

Страница 17: ...membrane Several techniques for solution exchange are available These include gravity feed pump driven devices or manually applied pressure driven systems In general fresh solution is added to the bo...

Страница 18: ...plifier and can also be used re assess the performance of the amplifier at a later time To perform these tests you will need BC 535 Bilayer Clamp amplifier included headstage included model membrane F...

Страница 19: ...auto trigger 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...

Страница 20: ...UP DOWN TOGGLE switches in the HOLD block adjust hold potential until the meter reads 0 mV Place the amplifier into standby Input noise test without model membrane Remove the model membrane Insure tha...

Страница 21: ...st With the model membrane still connected set the oscilloscope voltage base to 50 mV div Set the Im GAIN on the amplifier to 1 mV pA Place the amplifier into operate Activate CAP TEST mode by setting...

Страница 22: ...observe the resulting signal on the oscilloscope You will see a large transient on the leading edge of both the upward and downward excursions of the signal This transient or spike represent the larg...

Страница 23: ...ngenuity and training once the hole has been coated the cup is inserted into the chamber and both the cup and chamber filled with the appropriate solutions Two methods are presented below One method t...

Страница 24: ...CTOR SWITCH is in the offset position If using the manual approach the control should be advanced slowly since a small change in rotation will result in a large change in the current through the open...

Страница 25: ...a thin lipid film across the open aperture reminiscent of making bubbles when you were a kid Alternatively the membrane can be formed by momentarily occluding the hole with the end of the lipid coate...

Страница 26: ...then connected via a 14 16 gauge braided copper wire to an external central ground point which acts as the absolute reference for all devices A bar of this type is provided in Faraday cages supplied b...

Страница 27: ...ground Doing so will create a ground loop and increase noise levels within the data This condition can be avoided by disconnecting the oscilloscope chassis ground from the common ground point when con...

Страница 28: ...h in meters Likewise we know that that the steady state charge on a capacitor can be expressed as CV q 2 where q is the charge on one capacitor plate in Coulombs and V is the potential between the pla...

Страница 29: ...nstrument gain For example a 100 pF membrane would yield a 1000 mV square wave p p when the amplifier gain is set to 10 mV pA Suggested References 1 Ion Channel Reconstitution edited by C Miller Plenu...

Страница 30: ...l selectable from 0 5 to 200 kHz in 1 2 5 steps or bypassed for full amplifier bandwidth Capacity compensation FAST 0 10 s and SLOW 0 10 ms with adjustment of amplitude and time constant for each rang...

Страница 31: ...1999 pA full scale Power 100 125 or 220 240 VAC 50 60 Hz Dimensions H W D Case 9 42 25 cm 3 5 16 5 10 in Headstage 2 3 2 8 5 8 cm 0 9 1 1 2 25 in 1 8 m connecting cable Operating Conditions Equipment...

Страница 32: ...unused wire should be cleaned with ETOH before chloriding Previously chlorided wire should be cleaned before re chloriding Two methods for chloriding most commonly used are the plating techniques des...

Страница 33: ...als 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 in...

Страница 34: ...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 screwd...

Страница 35: ...000 4 8 EN610000 4 11 Manufacturer s Name Warner Instruments Manufacturer s Address 1125 Dixwell Avenue Hamden CT 06514 Tel 203 776 0664 Equipment Description Instrument Amplifier Equipment Class ITE...

Страница 36: ...ments Manufacturer s Address 1125 Dixwell Avenue Hamden CT 06514 Tel 203 776 0664 Equipment Description Instrument Amplifier Safety requirements for electrical equipment for measurement and laboratory...

Страница 37: ...BC 535 Preliminary Rev 060126 37 BC 535 Preliminary Rev 060126 37 Warner Instruments A Harvard Apparatus Company Warner Instruments A Harvard Apparatus Company...

Страница 38: ...ar or become black Alternatively Bilayer Lipid Membrane Many researchers now observe membrane formation electrically and have altered the acronym to mean the molecular bilayer formed from the orientat...

Страница 39: ...ransmembrane potential It should be noted that by this definition a transmembrane potential of 100 mV is still depolarized digital Quantized or discrete Normally refers to information manipulated by a...

Страница 40: ...in the closed state mean open time The average length of time a gating channel will remain in the open state mini jack A small plug on the headstage to which the electrodes are attached model membrane...

Страница 41: ...le variable resistor used for making fine adjustments to a circuit TTL Transistor Transistor Logic Voltage ranges used to define an on or off state in binary devices 0 0 8 V defines a logic 0 state an...

Отзывы:

Нет отзывов