The following settings are used to shear nuclear DNA to ~300 bp (range 100–500 bp): duty cycle, 10%; intensity, 5; cycles/burst, 200; and time, 20 s × 6. For small genomes, such as mtDNA, viral or plasmid DNA, the following settings should be used: duty cycle, 10%; intensity, 5; cycles/burst, 100; and time, 20 s × 3. CRITICAL The water-bath temperature should be 4 °C, and the water bath should be degassed for 30 min before shearing.
