I try to find sufficient parameters such as Hz of sonicator, sonication time, cycles and breaks...etc
Tobias's suggestions are appropriate, and trial-and-error is necessary because results also vary by sonicator setup. What size is your sample? Sonicating in a 1.5ml centrifuge tube is a different battle than sonicating 100 ml. One of the most important points is to make sure the temperature stays low. Sonication heats the sample up quickly. For ~50-100 ml, I use a stainless steel beaker in a salt/ice/water bath with a stir bar in the beaker and the whole ice-bucket on a stir plate (better than standing there shaking the ice bucket). On a 200W sonicator with a 1/2" tip, i'll run a 20-60% duty cycle with 50-80% max power. It's an analog sonicator so I can't give you actual delivered watts. The important thing is I don't start until the temperature is < 5C and don't let it get above 15C. When it warms up, I'll stop and wait until it's cold again. If you want to measure protein release, take 100 ul of the lysate at different time points, spin out the gunk and run a protein/Bradford assay. Keep sonicating until you don't see an increase in released protein levels.
I agree with Tobias and David. Try and error would help you to find the best protocol. Good lucks!
The above suggestions are correct, however in addition to the above lysozyme can be added to your sonicating mixture as well as protease inhibitor cocktails to increase the protein yield
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