Voltammetric & Amperometric Amplifier

The VA-10X (npi electronic) is a sensitive (picoampere range) current amplifier that can be used to detect quantel transmitter release (amperometry) from single cells in tissue culture.

For more information on the VA-10X amplifier please visit npi electronic website

Voltammetric & Amperometric Amplifier

The VA-10X (npi electronic) is a sensitive (picoampere range) current amplifier that is intended for voltammetric measurements with carbon-fiber microelectrodes in biological systems, where the total currents do not exceed 100 nA. It was designed at the Max-Planck-Institute for Experimental Medicine in Göttingen as an economically priced alternative to do-it-yourself systems and expensive commercial systems. It can be used for either DC amperometry using the built-in voltage source, or it can be operated with user-supplied external voltage waveforms (e.g. for cyclic voltammetry). The VA-10X is ideally suited for measurements from single cells plated onto glass cover slips and with carbon-fiber disk electrodes having diameters of 10 µM or less. However, it can also be used for measurements made on superficially located cells in tissue slices. The VA-10X is not recommended for use in in vivo recordings with carbon-fiber electrodes having long cylindrical measuring surfaces, because in this case currents approach the µA range.

The VA-10 is also available as module for the EPMS-07 system.

Feature of the VA-10X:

• Precise Voltage Source
  Internal voltage source for amperometry
• Variable Gain
  Gain from 0.5 to 50 in seven steps
• Variable Filter
  Output filter from 20 Hz to 20 kHz in 16 steps
• 3-electrode headstage
  Optional, on request
  The 3-electrode headstage provides a command potential that is independent from any bath potential.
• Electrophysiology in Parallel
  Simultaneous Electrophysiological Recordings Simultaneous
  recordings during voltammetric or amperometric investigations can be performed with most intra- and extracellular amplifiers with headstages with differential inputs (e.g. SEC-HSD headstage for the SEC-05/10 single electrode clamp amplifiers).

HEADSTAGE:
Input voltage range: ±1200 mV
Operating voltage: ±12 V
Enclosure: Size: 40 x 70 x 20 mm, grounded
Mounting plate: 50 x 70 mm, not conducting
Electrode connector: BNC with driven shield
Ground connector: 1 mm connector (black)
Driven shield output: 1 mm connector (red)
Input resistance: >10E+13 Ohms
Current range: ±12 nA into 100 MOhms

NOISE:
<1 pA

LP FILTER:
2-pole or 4-pole Bessel FILTER (1-pole or 8-pole Bessel FILTER on request)
16 corner frequencies: 20, 50, 100, 200, 300 500, 700, 1k, 1.3k, 2k, 3k, 5k, 8k, 10k, 13k, 20k Hz.

GAIN:
7-position rotary switch (x0.5, x1, x2.5, x5, x10, x25, x50 mV / pA)

VOLTAGE SOURCE:
COMMAND VOLTAGE set by 10-turn potentiometer, range: (1000 mV, polarity selectable with polarity switch (+, 0, -), display XXXX mV

OUTPUTS:
Impedance: 250 Ohms
FILTERED: BNC connector, sensitivity selectable with GAIN switch, FILTERED with LP Bessel FILTER
UNFILTERED: BNC connector, sensitivity selectable with GAIN switch

INPUTS:
Resistance: 1 MOhm

COMMAND VOLTAGE:
INPUT BNC connector, sensitivity: /10, also displayed

DIMENSIONS:
19" rackmount cabinet, 19" (483 mm), 10" (250 mm), 3.5" (88 mm)

POWER REQUIREMENTS:
115/230 V AC, 60/50 Hz, fuse 0.4/0.2 A, slow.

All downloads are in pdf format. Use Acrobat Reader to view. If you do not have the latest Reader, download it from the Adobe webpage for free

To save a pdf file to your local machine, right mouse click on link and choose "Save Target As...". You then choose the destination folder you want to save the pdf file to.

The VA-10X is delivered with standard headstage, cable set and connectors for electrode connection and ground and a user manual. Below is a list of options and additional accessories (at additional costs).

• VA-10X: amplifier for voltammetry and amperometry
• VA-CFE: Carbon fiber electrodes - 5 micrometer diameter, using the Anodic Electrophoretic Deposition of paint(EDP) method.
• VA-CFE-H-BNC: Electrode holder for headstage with BNC connector
• VA-CFE-H-AXU: Electrode holder for AXON amplifier.