newer in axoclamp900a

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kay0205
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newer in axoclamp900a

         Hi,everyone~Thanks for your attention!
         I'm a newer in axoclamp900a and try to use this to do TEVC on oocytes. here's my config:axoclamp900a, digidata1440a and pclamp10.3. 
         I think the main problem is i don't know how to adjust the Pipette Capacitance Neutralization,gain,lag. I've tried this followed the Axoclamp 900A Manual. can anyone paste screenshot to tell me how to adjust these parameters?
         1. Pipette Capacitance Neutralization: it seems no matter what the value of Pipette Capacitance Neutralization, the sweep has no much change. i use the tuning 10nA.
         2. gain and lag: at the beginning, the sweep like a bow, after increase the gain it looks like the stepwaveform, but if a increase the lag, the gain can increase to 50000.......by the way, should i click the DC restore on?
         Thanks and Best Wishes!

The FFM
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 have you read the manual?
kay0205
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YES,I‘ve read it and followed

YES,I‘ve read it and followed the manual for several days.
Using the model cell, everything goes well, although i don't know what's the waveforms in pClamp means good because the manual shows in oscilloscope. That's why i want the screenshots to see the "good" waveforms in pClamp.
Using occytes, everything goes to mess. tomorrow i'll paste some screenshots to show. no square waveforms, no gains......

The FFM
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Good i'm glad you've followed

Good i'm glad you've followed the manual - I didn't want to appear rood, but I had to ask the obvious question to understand where you where in this troubleshooting process.

Are you sure that it is actually necessary for you to perform the pipette capacitance neutralization if you are doing TEVC on Xenopus oocytes?

For most oocyte TEVC applications, scientists do not do capacitance neutralization.

Are your step protocols so brief that the capacitance transient interferes with the signal?

kay0205
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I'm sorry that i left my USB

I'm sorry that i left my USB flash disk in the lab, so today has no screenshots.

Why i tried the  pipette capacitance neutralization? Because first i don't know here is no need to perform this, second I have no confidence in myself and the third waiting for the screenshots.

 Let's get to the point.
1. is the Rpipette about 30-40 Mohm(with 3M KCl) used for TEVC too high? if so, does this bring large noise? Using the model cell in the bath postion, the noise is about 0.5 mv peak to peak; but using the pipette in the bath, the noise  is about 10 mv peak to peak. I've already re-chlorined, changed the holder. in the faraday cage.

can this noise acceptable in TEVC? what else can i do to improve the noise?any suggestions are welcome~

kay0205
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this is the first time i put

this is the first time i put my pipette into bath, the waveform make me to perform  Pipette Capacitance Neutralization. but finally I found this is caused by the anatomical lens which even don't have a lamp. after grounded, it becomes better as follows: to show the noise:

but this is not the end of the story, because the seal test:

actually this is a better one, most times, Turn to the TEVC, it oscillation......

I think the problem maybe is the too small tip of the pipette and the bad condition of the oocyte,right? because the model cell goes well, and I've alread  re-chlorined, changed the holder. in the faraday cage.
but can the bad shape of pipette can bring so large a problem?