Summary
The Model 2400 is a low-noise, full-featured intracellular/extracellular amplifier designed for voltage clamping using patch electrodes on single channels or whole cells. Its unique design allows fast intracellular current clamp measurements with sharp electrodes. Advanced circuit design techniques using field programmable gate arrays eliminated noisy microprocessors.
- Full-Function Patch Clamp Amplifier for both whole cells and patches
- True Current Clamp is 100% stable with bandwidth of 200kHz.
- Switchable Dual Resistive Feedback Headstage
- Capacity, series resistance, and whole cell compensation
- 4-pole Low-Pass Bessel Filters
- Internally generated test signals
- Telegraph outputs for all major front panel controls
- Independent hold, offset, and tracking circuitry
- Displays command potentials, cell currents, and voltages
Amplifier current gain is extremely flexible as it can accept any of four resistive feedback probes. Each probe has two feedback resistors selected from the following values: 10 MΩ, 50 MΩ, 100 MΩ, 1 GΩ, 5 GΩ, and 10 GΩ. The wide range of feedback resistors means currents can be recorded with outputs of 1 mV/nA to 10 mV/fA. The standard probe sent with each unit is the 100 MΩ/10 GΩ version, but other values can be selected.
Unlike other patch clamp amplifiers, the Model 2400 has a voltage follower in the probe. This allows this amplifier to be a true fast current clamp amplifier with no instability. An integrated four pole low pass Bessel filter provides flexible signal conditioning. Fine tuning capacity compensation is available to eliminate virtually all electrode-induced transients. Calibrated whole cell compensation provide easy display of membrane capacitance and access resistance.
A host of command potentials are integrated internally within the model 2400, including an automatic tracking command to zero the membrane current, manual controls for offset and holding potentials, and an easily readable digital display. For signals that are more complicated, an external command input with different scaling factors is available for use with any signal source.
A digital meter provides accurate values of command signals and membrane currents or voltages, the true RMS noise of the amplifier and experimental setup, the cut off frequency of the low pass filter, and the overall gain of the amplifier plus probe.
Series resistance compensation provides the researcher with the option of introducing either or both predictive and corrective compensation from zero to 100%. Fine and coarse controls for lag provide sensitive control to minimize oscillation produced by compensation close to 100%.
Separate compensation controls exist for eliminating transients seen during current clamp experiments when the bridge balance is used.
Telegraph outputs provide analog voltage equivalents of front panel settings including error conditions, amplifier mode and gain, Cmembrane, RMS noise, and low pass filter cut-off value. These telegraphs allow the Model 2400's front panel settings to be automatically recorded by your system software.
For those who need extra large bandwidths, the raw bandwidth of the entire amplifier may be adjusted via a rear panel potentiometer.
A second powered probe input is available for use as a bath signal input.
Specifications
Probe Gain and Bandwidth
| Feedback Resistor | Probe Gain | Maximum Current | Minimum Bandwidth |
| 10 MΩ | 10 mV/nA | 1000 nA | 100 kHz |
| 100 MΩ | 100 mV/nA | 100 nA | 100 kHz |
| 1 GΩ | 1 mV/pA | 10 nA | 60 kHz |
| 10 GΩ | 10 mV/pA | 1 nA | 40 kHz
|
Probe Case Size
- 2.1" (54mm) long x 0.8"(20mm) high x 1.4"(36mm) wide
- BNC input connector
- 1 mm ground pin connector
Maximum Instrument Noise
Voltage clamp modes measured with the internal 4 pole Bessel filter and minimum external noise.
| Headstage Resistor (Ωs) |
| Bandwidth | 10 M | 100 M | 1 G | 10 G |
| 1 kHz Theoretical Limit | 0.002 nA | 0.4 pA | 0.1 pA | 0.04 pA |
| 1 kHz | 0.003 nA | 0.5 pA | 0.17 pA | 0.08 pA
|
Current clamp modes have noise levels less than 20 µV with inputs shorted.
Internal Bandwidth
For voltage clamping only the bandwidth is settable from 10 kHz to 100 kHz.
Membrane Current Output Range
| Probe Feedback Resistor | Output Range |
| 10 MΩ | 10 mV/nA-1 V/nA |
| 100 MΩ | 100 mV/nA-10 V/nA |
| 1 GΩ | 1 mV/pA-100 nV/pA |
| 10 GΩ | 10 mV/pA-1 V/pA
|
Membrane Voltage Output Range
Filter
- 4 pole Bessel filter with 6 pre-set values, and bypass: 0.5 kHz, 1.0 kHz, 2.0 kHz, 5.0 kHz, 10.0 kHz, and 20.0 kHz.
- 0.1 kHz resolution
Capacity Compensation
- Voltage clamp:
- FAST1: 0-10 pF, 0.2-2 µs
- FAST2: 0-1 pF, 0.1-10 ms
- Current clamp
Whole Cell Compensation
- Raccess: 0-100 MΩ
- Cmembrane: 0-100 pF
Series Resistance
- RsPre: 0-100%
- RsComp: 0-100%
- LagCoarse: 1-100 µs
- LagFine: 1-10 µs
DC Balance
- Up to the value of the low feedback resistor in the probe
Hold Command
- Voltage clamp: ±200 mV
- Current clamp:
| Probe Resistor | 10 M | 100 M |
| Command Range | ±200 nA | ±20 nA
|
Offset Command
- Voltage clamp: ±100 mV
- Current clamp: ±1 V
Speed Test Command
- Used in voltage clamp only.
- Probe High Gain: 0.2 nA p-p at 60 Hz
- Probe Low Gain: 1 nA p-p at 60 Hz
Vcomp Command
Iresist Command
External Command
- Voltage clamp: 100 mV/V with the external switch set to 410, 20 mV/V with the external switch set to 450
- Current clamp:
| Probe Resistor | 10 M | 100 M |
| 410 range | ±100 nA/V | ±10 nA/V |
| 450 range | ±20 nA/V | ±2 nA/V |
Headstage
The probe is both a current to voltage converter and a voltage follower. The current to voltage converter used in voltage clamping has one of two high value resistors used for amplifying membrane currents. Below is a table of the different probes you can purchase from A-M Systems, Inc. and their feedback resistors.
Note: For proper operation, the purchase of a Model 2400 Patch Clamp Amplifier Headstage and an electrode holder is required.
| Catalog Number | Probe Low Gain
Resistor Value (Ωs) | Maximum Current | Probe High Gain
Resistor Value (Ωs) | Maximum Current |
| 880210 | 10M | 1000nA | 1G | 10nA |
| 880218 | 10M | 1000nA | 10G | 1nA |
| 880222* | 100M | 100nA | 10G | 1nA |
* The most commonly ordered headstage is the #880222 10G/100M headstage. A headstage must be ordered at time of instrument purchase.
The probe has three connections, the input BNC, a ground jack, and a guard jack.
The input BNC will hold any BNC style electrode holder, and is where any input signal should be connected. The center conductor is connected through a current limiting resistor to a field effect transistor amplifier. Other than the current limiting resistor there is no other protection to the probe so care must be taken to avoid electrostatic discharges. The outer conductor of the BNC is connected to a guard circuit. The guard is a buffered version of the input voltage, so care must be taken not to ground the outer conductor of the BNC.
Downloads
Buy
The Model 2400 ships complete with:
- Operator's manual and Rack mount hardware
- Model Cell
Note: For proper operation, the purchase of a Model 2400 Patch Clamp Amplifier Headstage and an BNC-compatible electrode holder is required. A Model 2400 Headstage will be automatically added when you add a Model 2400 to cart. Please select a BNC-compatible glass electrode holder to your cart.
| 880000 |
Model 2400 Patch Clamp Amplifier, 110 V, 60 Hz |
$2,975.00
|
Quantity: |
| 880005 |
Model 2400 Patch Clamp Amplifier, 220 V, 50 Hz |
$2,975.00
|
Quantity: |
| 880210 |
Patch Clamp Headstage, 1G/10M Feedback Resistors |
$350.00
|
Quantity: |
| 880218 |
Patch Clamp Headstage, 10G/10M Feedback Resistors |
$350.00
|
Quantity: |
| 880222 |
Patch Clamp Headstage, 10G/100M Feedback Resistors |
$350.00
|
Quantity: |
| 880260 |
Model Cell |
$100.00
|
Quantity: |
| 688000 |
Rack Mount Hardware for 3.5" Instruments |
$25.00
|
Quantity: |
| 749924 |
Extended Warranty, 2 Year, Model 2400 with headstage |
$250.00
|
Quantity: |
