PClamp v9

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Picocurrent
Picocurrent's picture
PClamp v9

Hi,
Having some problems with pClamp v9 (using 200B amp).  When setting up a cell to clamp and attaining a GOhm seal, the resistance value as observed in the 'multiclamp' control window (channel 1 check box) is fine and reads correct (checked with model cell), the problem is that the values given when you open the 'seal test' window in Clampex are wildly different and with the model cell doeas not even calculate a value.  Any ideas?  Settings off somewhere?
Thanks.
 

cherian.lijo
cherian.lijo's picture
Hi,

Hi,

I would like to suggest  you to check in edit protocol, go to input tab and check the channels defined. First for Imemb and second with Vm. (This is the setting I use, So try to check with other setups in your lab and define the channels properly)

The FFM
The FFM's picture
Err the Muliclamp software

Err the Muliclamp software doesn't work with a 200B amplifier does it?  You need to use a Multiclamp amplifier - You said you have a axopatch 200B which is a totally different device

You need to plug in the gain, frequency and and Cm outputs in the back of your amplifier to available slots on your digidata.  If you have an old digidata like a 1200 series you will have to use three of the analog inputs on the front.

If you have a newer 1322 or 1400 series then there are Telegraph input sockets on the back of the digidatas that you can use (0 through 3).

In pclamp 9 you then need to go to Configure>telegraphed Instrument

tell it for which signal you are telegraphing - It will be for your membrane current which is usually Analog Input #0

There is a telegraph instrument drop down menu - select Axopatch 200B
 Now in the telegraph connections menu select the digidata inputs into which you plugged the BNC cables from the Gain Frequency and Cm outputs from the amplifier

Click OK

Go to your lab bench  - (the little button with the picture of a BNC cable in the top right of the tool bars)

Check your Input Analog IN #0 - And in the signals window select I_Stest0

If the telegraphing is working correctly - the scaling should be automatically calulated and you will be able to do a seal test on a model cell.

In Configure>Seal Test setup  you should check that the input signal is I_Stest0 (pA) and that the seal test signal is Cmd (0) or whatever you chose to call it in lab bench.

Oh and of course go to Configure>Digitizer and make sure that your digidata is activated and calibrated before you try to record...otherwise you'll just be running in Demo mode

Picocurrent
Picocurrent's picture
Hi,

Hi,
Thanks for that.  Sorry there was a typo, it's a 700B that we run!  I guess that makes more sense now.  Everything you said makes absolute sense and after a day in the lab with manuals on my lap I think I've cracked it... although there are a couple of other very small functions that I may post about later. 
Thanks a lot for all the advice give, appreciate it.