Re: [DIYbio] Re: Designing a DIY Gene Electroporator

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In response to "is there a standard wave?", I'll just jump in and say:
though I've barely ever worked with electroporation, and know not what
I say, I used to work with those who did. And their impression, from
the inside, was that no: there is no standard waveform that will give
useful, if suboptimal, results across the board.

Waveform varied pretty widely even between cell types extracted from
the same species, and some strains were just too 'ard to EP without
serious work to optimise, whereas others would accept DNA if you even
threatened to buzz them a little.

That said, some thoughts:
A) EP would never have taken off if there weren't a wide margin for
error, because without knowing in advance the waveforms for this or
that species, no successes would have been likely. So some lassitude is
likely among species that are worth turning to EP to transform, to
begin with, whereas with those that don't respond without careful
optimisation, perhaps it's better to either await empirical results and
custom-build an EPorator, or turn to another method of transformation.

B) Piezos and other "dirty" electroporators might suggest that a
chaotic or noisy source offers the best route to general-purpose
transformation. That is:
- Species tend to be picky about response to particular waveforms
- Too much electricity is the chief killer when EPorating
- Efficiency at the correct waveform is *probably* scalar with
duration, implying that the most important bit is getting *any* time
at the right frequency, with everything else being a bonus.
So, perhaps rather than seeking a one-true-waveform, it might be worth
investigating a waveform that scales from one frequency to another,
covering everything in between, within the timeframe that delivers a
generally-accepted-as-OK current load on the cell suspension. So if the
cell responds to any of the intermediate frequencies or waveforms,
it'll get at least a few instants of it?

Just some thoughts, poorly grounded in experience. :)

Cathal

On Sun, 3 Nov 2013 12:15:27 -0500
"Meredith L. Patterson" <clonearmy@gmail.com> wrote:

> Adding TQ to this discussion.
>
> Cheers,
> --mlp
>
>
> On Sun, Nov 3, 2013 at 6:43 AM, Nathan McCorkle <nmz787@gmail.com>
> wrote:
>
> > So with a few capacitors like this (microwave capacitor, 2kV 1uF) in
> > parallel (capacitance adds in parallel):
> >
> > http://www.ebay.com/itm/BiCai-1-05uF-HV-Microwave-Capacitor-CH85-21105-2100V-AC-New-/171157909970?pt=LH_DefaultDomain_0&hash=item27d9ce71d2
> >
> > or $1.75 each in packs of 20:
> >
> > http://www.aliexpress.com/item/Free-Shipping-Imported-microwave-high-voltage-capacitor/1077977860.html
> >
> > would this $7 7kV power supply be useful, could you drop the voltage
> > with a divider to get 1.8kV?
> >
> > http://www.aliexpress.com/item/New-DC-3V-to-7KV-7000V-High-voltage-Generator-Boost-Step-up-Power-Module-free-shipping/1326494805.html
> >
> > Then seems like all you'd need is an arduino, a gate driver IC, and
> > a MOSFET or 3.
> >
> > Are these big clunky caps really the 2013 best-fit part?
> >