Axon instruments multiclamp 700a manual

Please provide a valid price range. Buying Format. All Listings. Accepts Offers. Buy It Now. Item Location. Canada Only. North America. Shipping Options. Free International Shipping. Local Pickup. Free Local Pickup. Show only. It includes both tutorial-style guidance and technical details for reference. Page General Advice For this reason, it is important to use a good, drift-free micromanipulator for the electrode, and to secure the tissue or cells in the chamber so they cannot move MultiClamp A Theory and Operation, Copyright , Axon Instruments, Inc.

A grid is easily made as follows. Bend a piece of 0. We have found empirically that the noise in the recordings depends on which headstage is grounded and what mode it is in V-Clamp or I-Clamp. Page Patch Clamping Digital computers can generate considerable electrical noise, both via the power ground and via radiative interference from the monitor.

For optimal noise performance of the MultiClamp A, careful attention should be paid to the placement of the computer. For example, the monitor should not be placed immediately above or below the MultiClamp A in the instrument rack. Fill a patch pipette with internal solution and secure it firmly in the pipette holder fill the patch pipette with external solution if cell-attached recording is the goal.

Be sure to support the Apply about 30 mbar of positive pressure to the holder tubing, then lower the pipette tip into the bath. Any voltage offset between the bath electrode and the patch electrode will show up as a non-zero tracking voltage on the I nA meter of the MultiClamp Commander. Page 50 The best gigaseals are those that form nearly instantaneously. If a seal does not form within about a minute, continued suction is usually pointless.

It is best to change electrodes and try again. This subtracts a scaled divided by the resistance version of the command pulse from the membrane current signal, and is particularly intended for use at high gains where the interesting single-channel currents are sitting on top of a leak current that may saturate the digitizing interface. This circuit delivers a pulse of 1 V DC to the patch for variable durations ranging from 0. Generally speaking it is not a good idea to do this in the whole-cell configuration, because whole cells may contain background currents that have some dependence on voltage.

Page Perforated-Patch Recording Figure 3. The Membrane Test feature of Clampex v. Page Low Noise Techniques Figure 3. Going whole-cell: capacity transients observed during amphotericin partitioning.

To realize this performance the user must pay close attention to other sources of noise. This is because the total rms noise of a patch clamp recording is the square root of the sum of the individual squared rms noise sources. The loss factor is related to the power dissipated in the dielectric.

Since energy is lost in the dielectric, dielectrics , glasses are commonly referred to as "lossy". We recommend two glasses for noise-critical work: Corning and quartz. Both have been successfully sealed to many different cell types. Page 58 Therefore, for the most demanding low-noise applications it is recommended that an Axopatch B is used. Polycarbonate was experimentally found to produce the lowest noise among ten substances tested. It was only slightly better than polyethylene, polypropylene, and Teflon, but was much better than nylon, Plexiglass, and Delrin.

Page Sharp Microelectrode Recording Signal Generator One last potential noise source to consider is the noise in the signal generator that provides the command. In the MultiClamp A we have succeeded in minimizing this noise by heavily attenuating the external command. Page Sharp Microelectrode Or Patch Electrode Microelectrode Properties Users of sharp microelectrodes spend far more time than patch clampers worrying about the properties of their electrodes.

For best results, the microelectrode voltage must settle rapidly after a current pulse, and the microelectrode must be able to pass current without large changes in resistance. The important factors that need to be considered are discussed below. Page 62 Another method is to coat the microelectrode with Sylgard or Q-dope model airplane glue.

Changes in this tip potential are indistinguishable from changes in the membrane potential and can therefore be a serious source of error. Fill a microelectrode with internal solution and secure it firmly in the pipette holder. Be sure to support the headstage with your other hand so that the micromanipulator will not have to absorb your force. Move the electrode tip close to where cells are likely to be encountered, and then increase Pipette Capacitance Neutralization in the MultiClamp Commander to give the fastest step response.

This chapter provides details of the theory and operation of the MultiClamp A, beyond what is available in the On-line Help. The information in this section is gathered under a number of broad topics, arranged in alphabetical order. Page Audio Monitor DC signal, e. Page 70 2. This allows dedicated use of the headphones or external speakers by the MultiClamp A. Figure 4. Possible Audio configuration 2.

Page 71 3. Page Bath Headstage And Electrodes The Bath Headstage is used when recording from cells with a large conductance, in order to minimize errors due to current flow through the bath electrode.

Page 73 This is achieved using a virtual-ground circuit, the bath headstage. These headstages attach to the MultiClamp A via the rear-panel pin D connector. Page 76 Neutralization should also be set. See Capacitance Neutralization. Both settings can be monitored continuously through the experiment by injecting a small current step near the beginning of each data sweep.

Page Buzz An appropriate duration can be found for most cells that is sufficiently long to allow penetration of the membrane but short enough that the cell is not damaged after penetration. Page 80 This takes longer to charge to its final value and is compensated by the C Slow controls. Page 81 Furthermore, as in the case of the electrode capacitance transient, the whole-cell transient may saturate the circuitry of the MultiClamp A or downstream instruments if left uncompensated.

Finally, whole- cell capacitance compensation is necessary for series resistance compensation. For all of these reasons, it is desirable to electronically compensate the capacitance of the cell.

Page 82 R to C2, the series resistance compensation circuitry can operate without causing the headstage input to saturate. Page 83 The I trace in the figure was recorded using an oscilloscope probe connected to the internal circuitry.

It is easy to mistakenly think that the time course for charging the membrane is very fast but this is clearly not the case. Page 84 This can be achieved by filtering the command stimulus before it is applied to the cell. This filtering can be done within the MultiClamp A.

Primary Method for Neutralizing C A special technique is used in the CV-7A headstage to keep the contribution to from the input amplifier as small as possible. Page 86 Sometimes the overshoot is difficult to see. Page 87 Use of capacitance neutralization is less desirable than physically minimizing C since the neutralizing circuit adds noise to the voltage signal.

This noise has been minimized in the CV-7A headstage of the MultiClamp A by using low-noise amplifiers and small injection capacitors, but it is still significant. Page Clear Whether to use a hyperpolarizing or depolarizing current depends on the preparation and must be determined by trial and error. Like Buzz, the mechanism for impalement is unknown. Page Electrochemistry For biological applications, the sensor is typically a carbon-fiber microelectrode.

Examples of electro-active biological chemicals are dopamine and norepinephrine. The MultiClamp A, like the Axopatch B, can be used to measure the electrical signals generated by the presence of these chemicals.

Page 90 The temporal resolution is determined only by the response times of the sensor and the voltage clamp. Both cyclic voltammetry and amperometry can be performed by the MultiClamp A without modifications. Such modifications are necessary for some other Axon amplifiers because electrochemistry typically requires larger voltage commands than is usual for patch or intracellular recording.

Note that this is a DC-coupled input, so be sure that the external pulse generator is correctly calibrated so that zero volts really correspond to zero. Page 92 Gains tab under Current Clamp.

It was tested, cleaned and comes with day warranty. The Digidata A is a low-noise high-resolution bit data acquisition system for electrophysiology. MD Axon Digidata The Digidata B is a low-noise high-resolution bit data acquisition system for electrophysiology.

Axon Instruments MultiClamp A is a versatile computer-controlled amplifier capable of single-channel, whole-cell and ion-selective electrode recordings, as well as voltammetry and amperommetry. Condition: This amplifier was tested and comes with day warranty. Condition: This amplifier is used, and in excellent condition.

The original price of this MultiClamp Condition: This amplifier comes with one CV-7B headstage. It is used, and in excellent condition. My account. Sign out. Browse the mobile site. Contact Sitemap.