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OPERATING INSTRUCTIONS AND 

SYSTEM DESCRIPTION OF THE 

VA-10X

 

VOLTAMMETRIC AND 

AMPEROMETRIC AMPLIFIER 

 

 
 
 

VERSION 7.0 

npi 2014 

 

npi electronic GmbH, Bauhofring 16, D-71732 Tamm, Germany 

Phone +49 (0)7141-9730230; Fax: +49 (0)7141-9730240 

[email protected]; http://www.npielectronic.com 

Содержание VA-10X

Страница 1: ...SCRIPTION OF THE VA 10X VOLTAMMETRIC AND AMPEROMETRIC AMPLIFIER VERSION 7 0 npi 2014 npi electronic GmbH Bauhofring 16 D 71732 Tamm Germany Phone 49 0 7141 9730230 Fax 49 0 7141 9730240 support npielectronic com http www npielectronic com ...

Страница 2: ...Components 5 4 VA 10X System 5 4 1 System Description 5 4 2 Description of the Front Panel 5 5 Headstage 10 5 1 Headstage Elements 10 5 2 3 Electrode Headstage optional 11 6 Operation 12 6 1 Setting up the VA 10X Voltammeter 12 6 2 Testing Basic Functions of the VA 10X 14 Open Circuit Test 14 DC Accuracy 14 Dynamic Test Frequency Response 15 6 3 Carbon Fiber Electrodes 15 6 4 Counter Electrode 16 ...

Страница 3: ...is to be operated only at 115 230 Volt 60 50 Hz AC Please check for appropriate line voltage before connecting any system to mains Always use a three wire line cord and a mains power plug with a protection contact connected to ground protective earth Before opening the cabinet unplug the instrument Unplug the instrument when replacing the fuse or changing line voltage Replace fuse only with an app...

Страница 4: ...a DC potential is applied to a carbon fiber microelectrode The applied potential appears at the interface between the carbon and the mammalian ringer solution If the potential is much greater than the redox potential for a given transmitter then molecules of transmitter diffusing to the carbon surface are oxidized rapidly yielding a current that can be measured The sensitivity of the amperometric ...

Страница 5: ...ce 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 ...

Страница 6: ...______________________________________________________________________________________________________ ___________________________________________________________________________ version 7 0 page 6 Figure 1 VA 10X Front panel view ...

Страница 7: ...5 OUTPUT UNFILTERED connector 3 OVER OVER LED The VA 10X has an over voltage indicator with two LEDs which light up if the amplifier is near it s positive or negative limit 10 V 14 OUTPUT FILTERED connector The OUTPUT FILTERED BNC connector provides a voltage that is proportional to the current passed through the electrode mV pA with GAIN 1 This voltage is FILTERED by a Bessel filter see 4 and sca...

Страница 8: ...f an external voltage source is used the 3 position toggle switch controlling the internal voltage source 6 should be set to 0 If the switch is set to or the voltage at the electrode is the sum of the external voltage and the internal voltage source COMMAND unit The COMMAND unit consists of 6 COMMAND polarity switch 7 COMMAND potentiometer and 8 COMMAND voltage display 6 COMMAND polarity switch Th...

Страница 9: ...AND potentiometer 7 multiplied by 10 and the INPUT voltage at the INPUT 10 connector 10 divided by 10 12 FILTER MONITOR connector BNC connector that monitors the setting of the FILTER switch The FILTER is monitored in steps of 1 V as the FILTER knob is dialed clockwise 8 V 7 V 13 GAIN MONITOR connector BNC connector that monitors the setting of the GAIN switch The GAIN is monitored in steps of 1 V...

Страница 10: ...MMAND command potential output 4 headstage cable to amplifier 5 REFERENCE not installed In the 2 electrode headstage the REFERENCE is not installed The table indicates whether the headstage is equipped with the standard feedback resistor 500 M or with a different one It is also marked whether the headstage is in 2 electrode or in 3 electrode configuration The electrical connections are made like i...

Страница 11: ...d Caution Please always adhere to the appropriate safety precautions see chapter 1 Please turn power off when connecting or disconnecting the headstage from the HEADSTAGE connector 5 2 3 Electrode Headstage optional The 3 electrode headstage differs from the standard headstage in having an additional 1 mm electrode connector REFERENCE between the GROUND and COMMAND connectors for measuring the bat...

Страница 12: ...lease turn power off when connecting or disconnecting the headstage from the HEADSTAGE connector Remember that the shield of the BNC connector and the enclosure of the headstage are linked to the command potential output driven shield configuration and must not be connected to ground To improve noise reduction of the setup the faraday cage and the microscope may be connected to the INTERNAL GROUND...

Страница 13: ...BNC cable from the data acquisition system to GAIN MONITOR 13 Figure 1 and or the FILTER setting by connecting a BNC cable from the data acquisition system to FILTER MONITOR 12 Figure 1 If you intend to use an external voltage source e g for cyclic voltammetry connect your external voltage source to the INPUT 10 mV connector 10 Figure 1 Remember that the input voltage will be scaled down by a fact...

Страница 14: ... at zero e g with a digital meter Then do the following tests Open Circuit Test Do not connect anything to the electrode BNC With no command signals the current should be zero Connect a pulse to the command input BNC connector You should observe only capacitive transients and NO current during the pulse DC Accuracy Connect a 100 M or another high value resistor from the electrode BNC to ground Cau...

Страница 15: ...aluate the range of linearity of the amplifier and also the frequency response The BOOSTER is set correctly if the current output is as square as possible This also depends on the quality of the triangle wave at the 1 pF capacitor The effect of the gain stage and filters can be tested easily if these tests work Gain stage When testing the DC accuracy see chapter 0 change the setting of the GAIN an...

Страница 16: ...r than 650 mV is sufficient for measurements of all major oxidizable transmitters that have been studied so far To generate a command potential for DC amperometry there should be no control voltage at the INPUT 10 mV BNC and the INPUT 10 mV coupling switch should be set to OFF The 3 position command toggle switch should be set for example to the position Then the desired potential can be dialed in...

Страница 17: ...h C 2003 Calcium dependence of action potential induced endocytosis in chromaffin cells Pflugers Arch 445 540 546 Chan S A Polo Parada L Landmesser L T Smith C 2005 Adrenal chromaffin cells exhibit impaired granule trafficking in NCAM knockout mice J Neurophysiol 94 1037 1047 Ciufo L F Barclay J W Burgoyne R D Morgan A 2005 Munc18 1 Regulates Early and Late Stages of Exocytosis via Syntaxin indepe...

Страница 18: ...6 tetrahydropyridine lesioned mouse model of basal ganglia injury J Neurosci 27 5291 5300 Wang P Wang C T Bai J Jackson M B Chapman E R 2003 Mutations in the effector binding loops in the C2A and C2B domains of synaptotagmin I disrupt exocytosis in a nonadditive manner J Biol Chem 278 47030 47037 Wang C T Bai J Chang P Y Chapman E R Jackson M B 2006 Synaptotagmin Ca2 triggers two sequential steps ...

Страница 19: ...ong M G James C D Craighead H G Lindau M 2002 An electrochemical detector array to study cell biology on the nanoscale Nanotechnology 13 285 289 Hafez I Kisler K Berberian K Dernick G Valero V Yong M G Craighead H G Lindau M 2005 Electrochemical imaging of fusion pore openings by electrochemical detector arrays Proc Natl Acad Sci U S A 102 13879 13884 Spégel C Heiskanen A Acklid J Wolff A Taborysk...

Страница 20: ... 107 112 Paras C D Kennedy R T 1995 Electrochemical detection of exocytosis at single rat melanotrophs Anal Chem 67 3633 3637 Smith P A Duchen M R Ashcroft F M 1995 Fluorometric and amperometric study of calcium and secretion in isolated mouse pancreatic beta cells PflugersArch 430 808 818 Souvannakitti D Kumar G K Fox A Prabhakar N R 2009 Neonatal Intermittent Hypoxia Leads to Long Lasting Facili...

Страница 21: ...ional 48 dB octave corner frequencies 20 50 100 200 300 500 700 1 k 1 3k 2k 3k 5k 8k 10k 13k 20k Hz GAIN 7 position rotary switch x0 5 x1 x2 5 x5 x10 x25 and 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 50 Linear voltage range 10 V FILTERED BNC connector sensitivity selectable with G...

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