[Open_electroporator] culture shock tests on live cells

John Griessen john at cibolo.com
Thu Jul 13 15:19:01 UTC 2017


On 07/11/2017 12:25 PM, John Griessen wrote:
> so you might try:
>> a(150, 4, 92)      # which is the default currently
>> pulse()                # you'll see very fast pulsing, with very low HV ripple
>> a(3194, 684, 6)  # set to replicate John's original settings
>> pulse()                # you'll see the low and HV pulses like John's
>> original settings

OK.  This above is the info we need in order to make a test suite.

a(150, 4, 92) makes a voltage that tests the high range of voltage.

Since your machine has a capacitor fallen off, (I apologize for my weak soldering with
soldering iron instead of IR reflow), it won't go as high, but we don't know how much of
a shortfall it will have -- it won't be a linear interpolation.  If we guess some numbers to go higher and
if hits the limit of some of the component capacitors and diodes, the machine dies.

So here is a set of parameters you could use on separate loadings of the cuvette to see if
some survive better and if the volt threshold of poration is reached at all:

Plug in the culture shock to USB, and see a prompt >

 > a(150, 4, 92)
 > pulse()

reload cuvette, save and mark that cell suspension [a(150, 4, 92) 2mm gap]

 > a(150, 4, 65)
 > pulse()

reload cuvette, save and mark that cell suspension [a(150, 4, 65) 2mm gap]


 > a(150, 4, 32)
 > pulse()

reload cuvette, save and mark that cell suspension [a(150, 4, 32) 2mm gap]

This last one has a slight risk of killing the machine, since it goes higher and the lack
of one cap on the input side may not lower the energy transfer per switcher pulse very much...

 > a(150, 4, 102)
 > pulse()

reload cuvette, save and mark that cell suspension [a(150, 4, 102) 2mm gap]


Those values are likely to get some results on one of them if the machine still functions.
You could also try much higher effective field strengths by using a 1mm cuvette
instead of the 2mm cuvette I sent with the machine.  I recommend that instead of using the fourth
set of parameters.

There is no sanity check the machine is working since you have no test equipment to measure its output safely.

You could send it back for me to rework if you like.

Sorry I can't give you more certainty.  Thanks in advance for any testing work you do.

-- 
John Griessen
cibolo.com  Austin TX  building lab gear for biologists


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