Sonication of bacterial samples

When sample is 1.5ml of O/N grown bacterial pellet, resuspended in 0.5-1ml of lysis buffer, Sonication conditions are as follows:

Instrument settings
Press Timer: press 30 seconds then press Enter to confirm
Press Pulser: Cycle ON 5 seconds, cycle OFF 5 seconds Then: Enter to confirm.
Go to the amplitude knob (bottom right) set to 37% (Do not exceed 40%)

1. Place the tube on ice and immerse probe in the sample. (Probe should be immersed completely, without touching the tube at all!! bottom or sides!)
2. Press the Start key and pulse 3 times 30 seconds for each sample, until sample gets clear.  Place the probe inside the ice for 20 seconds between samples. (For prevention of sonicator over-heating!)
3. While sonicating, make sure sample is not getting hot as the sonication proceeds.

*Make sure the sample doesn’t move during the sonication (check that the tip is always immersed.

To check the efficiency of the Sonicator
1. At the end of the procedure check the total energy in Joules shown on the screen. Write the numbers!
2. Check differences between various tubes and tubes at the beginning of the procedure (first tube) and at the end of the procedure (last tube).
3. If the sample is heated during the 3 x 30’’: wait longer period of time between 30’’ pulses.

If your sample is in volume larger then 10ml you should replace the sonicator tip to the one suitable for larger volumes. Using the small tip, designed for smaller volumes will damage the tip and reduce the sonication efficency.