DNA extraction protocol optimized to maximize DNA yield, fragment length and microbial lysis. This protocol is a modified version of https://www.protocols.io/view/the-39-three-peaks-39-faecal-dna-extraction-method-kqdg34m9pl25/v2 The Three Peaks protocol is characterized by three separate lysis steps: (i) a 10% SDS-based lysis, (ii) a ProteinaseK-based lysis, (iii) a bead-beating-based lysis (optimized power and time settings). In between lysis steps, high-speed centrifugation collects the unlysed cell pellet at the bottom, leaving the supernatant containing DNA to be collected in a separate tube. At the end of the lysis steps three separate tubes containing DNA in a supernatant are processed separately with a column-based DNA isolation procedure, using the Power Soil Pro Kit (QIAGEN). The protocol yields ~40 mg (median) of total DNA/sample, ensuring enough DNA for multiple sequencing and other DNA-based procedures.
Coleen Mazzoni (Sun,) studied this question.