DIY sonication? What is out there?

[Nathan McCorkle]

I just lysed E. coli to get protein out for purification with a
sepharose column (aided by an overexpressed HIS tagged protein).

We used a Misonix sonicator, pulsing a few times with the output
showing 14-16 watts, the back of the machine said it runs at 22.5 khz.

Is there anything comparable or improvisable out there? Jewelry
cleaners, sonic toothbrush, etc???

--
Nathan McCorkle
Rochester Institute of Technology
College of Science, Biotechnology/Bioinformatics

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[Brian Degger]

Our local electronics chain (Maplin ) has a sonicators from £44,
These seem to run at 42kHz and 50 watts, so seems to be plenty of
power there. My worry is that there is too much energy and it might
heat up the proteins.
Be interesting to do side by side experiments,

Think there is a lot to explore with sonicators, this also came up
around using a device from a deconstructed misters
http://dx.doi.org/10.1016/j.partic.2009.09.006 Effective platform for
the generation of aerosol droplets and application in evaluating the
effectiveness of a MEMS-based nanoparticle trapping device

[Phil]

For the hardware engineers out there, I'd like to suggest designing a
DIY electroporator. There are 2 popular electroporator designs, the
exponential-decay (in which you choose one of several capacitors to
charge, and then discharge at high voltage into the leads to the shock
chamber), and the square-wave (which is a high-voltage power supply,
connected and disconnected from the leads at a user-defined duration
and frequency).

These seem like simple pieces of equipment, but they cost $6000-$8,000
new. I've never built anything to deliver thousands of volts, so
maybe that accounts for the expense?

It would be important to provide an output that can be attached to a
Bio-Rad or BTX shock chamber, both of which accept standard cuvettes.

[Simon Quellen Field]

Try one of these:

"http://www.scitoyscatalog.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=PZ&Category_Code="

Connect to the cuvette and click it a few times.

18 kilovolts exponential decay.

Should work fine.  Adjust the voltage down if you like using two resistors

as a voltage divider.

[Phil]

Sonicators are also useful for creating liposomes, to transfect cells
with DNA.

Standard protocols usually use 22,500 Hz IIRC.
Ultrasonics for cleaning jewelry uses about 40,000 Hz. From
http://www.upcorp.com/ultrasonic.html:

"Many technical articles claim that high frequencies penetrate more
and lower frequencies are more aggressive. The majority of the
ultrasonic cleaning that is done in industrial applications today uses
40 kHz as the base frequency. Lower frequencies, such as 20 - 25 kHz,
are used for large masses of metal, where ultrasonic erosion is of
little consequence. The large mass dampens or absorbs a great amount
of the ultrasonic cleaning power."

Also, sonicators for cell biology rely on having a sonicator with the
power focused at a sharp tip, inserted into a narrow test tube, so the
energy can be focused enough to disrupt cell membranes. That lets you
do it with about 50W sonicators. If the volume you were sonicating
were not in a test tube, you'd have to go to thousands of watts. So
you can't buy a $40 jewelry cleaner and disrupt cells in it.

I don't know if DIY sonication will be fruitful - the sonicator tip
has got to be machined precisely. If it can't vibrate at the right
frequency (probably with a standing wave?), it will burn out the power
supply but not generate any power at the tip.

[Brian Degger]

Thanks for the info about disrupting cells,
From that info maybe a better idea is a diyhomogenizer.
Slightly easier to machine.
So here, you are presurizing a solution containing the cells, passing
them through a needle valve and the cells burst when they go to a
normal atm pressure. Generally need a few passes, each time maybe 60%
of the bacteria get popped(based on pressures and organisms).
So you need a valve leading to a piston chamber leading to a needle
valve. A pressure gauge is useful.
Needs some fine machining and some good engineering.
Cheers B

--
Sent from my mobile device

[Cathal Garvey]

The homogeniser we use in the lab is a special bit for a rotary device that pulls a cell suspension in and forces it out, probably to achieve the same effect. I don't know whether this would be easier or harder than pressurising a solution and forcing it through a standard luer needle, for example.
I did discover today that bike shops stock CO2 cartridges and convenient pressure valves with standard screw-fittings, though, which could probably be easily adapted to all sorts of fun stuff like this!

--
letters.cunningprojects.com
twitter.com/onetruecathal
twitter.com/labsfromfabs

[Peter Nguyen]

If you guys are looking for a cheap way to lyse cells, what about non-mechanical methods? I know most of you guys probably already know this, but nobody has mentioned this in the thread. Traditionally, I've used lysozyme and freeze-thaw cycles to lyse my cells. Works fine. Also, the 'newer' cell lysis buffers that companies sell are often detergent-based, such as SDS. (Just google "detergent + cell + lysis") I'm sure there must be a cheap detergent alternative that can be used in a cheap formulation to disrupt cells without adversely affecting your protein.

If you really want to use sonication, though, I agree with Phil. DIY sonication isn't worth the trouble. Just buy one on e-bay, and make sure the kHz specs are in the right range.

-P