[Open_electroporator] culture shock micropulser code needs changes

John Griessen john at cibolo.com
Wed Jul 26 01:40:38 UTC 2017


There is a little problem with loading I saw just now,

If Mitchell's cell suspension in a 1mm cuvette measure less than a mega Ohm resistance total across the contacts,
we will have to do something before he is ready to test.  See below.

For more salty solutions I just noticed there will be a big drop compared to my earlier testing
probably because of the new program not using timers for the push and pull pulses to keep them
as precisely equal as possible.  I will be taking some of the nice functions Nathan coded
and moving them over to work with my timer-based pulser code, so the pulses are as equal as possible
and the currents can go up with as low as a 30 k Ohm load, as the early program does.  Nothing
else changed, so the different programs are the prime suspect in this different outcome I got
just now.  I noticed that when I reduced the period between pulses below 50, the output dropped
even if the number or width of pulses was large.

When I put a 33 k Ohm resistor across the output, and tried various combinations of
pulse period, width, and number, I could barely get more than 700V out of it.

So, to go back to being able to deliver 120 Watts of power for a short while, (and widen the range of
types of cells and buffers that can be electroporated), I will be testing with the old code again,
and adding the nice pulse() and a(period,width,number) functions to it.


More information about the open_electroporator mailing list