In our experience a greater orbital radii is more important the shaking speed. We have found faster kinetics with slow end over end agitation than with fast orbital shaking. However, the end over end shaker seem to be less durable. You may want to look at these two publications for a detailed examination of the physical factors involved in agitation enhancement of aggregation.

Second publication:

Cheaper alternative: -$440

http://www.ika.com/owa/ika/catalog.product_detail?iProduct=3319000&iCS=1&iProductgroup=179&iSubgroup=1

Also this one does not suffer from overheating if not done at room temperature which seems to be a problem with a lot of the other shakers.

Thanks for the links. One of the critical factors for us is that whatever piece of equipment we buy be capable of withstanding high temperatures or be able to incubate samples at a set temperature. Most of our aggregations are done at 37 C, and we have found that our VWR Vortex Mixer tends to get way too hot at 37 when running continuously. However, perhaps because of the intensity of its agitation, it brings aSyn up to its ThT fluorescence maximum in less than 24 h. Have you used the item you linked to in higher temperatures with no adverse effects?

We have run it for weeks at time with no problem at 37 or 45 C. The VWR Vortex mixer (we had the same model) broke after a few hours.

Did you consider stirring (with a bar magnet) as an alternative to shaking? Breaking the surface of the protein solution can be important for acceleration of the aggregation process

In principle should work, however it is difficult to stir multiple samples at a single time.

Hi Jeffrey, check out this one:

http://ika.com/owa/ika/catalog.product_detail?iProduct=3692500&iCS=1&iProductgroup=188&iSubgroup=1

Another way to accelerate aggregation is to add some glass beads into your samples. Proteins hate surfaces, whether it's water/air, water/glass or whatever

The glass beads is an interesting idea, Marina, and even without a multiple stirrer, they should increase the efficacy of orbital agitation. Have you used glass beads? If so, have you had a problem with aggregated protein sticking to the beads?

The glass beads were used often in a lab where I had a postdoc, where they studied aggregation of insulin. I don't think proteins like to stick to glass (in an aqueous media), because it's not hydrophobic. You might be able to find some articles about protein adsorption to glass vs. Teflon or something like that.

See the two articles earlier in the thread.

The problem with beads is the size of the beads are heterogeneous unless they are specially manufactured. This contributes to the sample to sample variation.

And the ones that are manufactured to a particular size are very expensive. We are currently looking to see if our VWR rep will let us try out one of the tray shakers, before we commit to buying. I will update with any results.

Just a suggestion for anyone who may read this in the future, but you could also use an incubated shaker (see link) rather than putting a shaker in an incubator.  That plus the glass beads should do the trick very well, and you won't have to worry about reducing instrument life due to extreme operating conditions.  Also, you'll end up with more throughput than you would by putting a small shaker in an incubator.

IF you end up putting any instrument in an incubator, be sure to check the manufacturer's specs and ensure that it's within the stated operating temperatures.  Those are there for a good reason.

http://orbitalshakers.net/collections/incubated-benchtop-orbital-shakers

Hi Everyone! Need advise for commercial scale of 50 -250 liters bulk protein mixing, will the standard agitator work in place of magnetic stirrer used in lab scale.