1. Take 1 ml from an overnight culture.
2. Spin and wash once with 1 ml water.
3. Resuspend in 500 μl lysis buffer.
4. Transfer to an eppendorf with acid washed glass beads.
5. Vortex 2 min. and then keep 2 min. on ice.
6. Prick the bottom of the tube with a needle.
7. Insert the tube in another tube and recover liquid phase (7000 rpm x 1min.).
8. Add 300 μl 6.2 M ammonium acetate pH 7.0.
9. Incubate 5 min. at 65 ºC, then 5 min. on ice.
10. Add 500 μl chloroform, vortex and spin 1 min. (7000 rpm).
11. Take 500 μl supernatant and precipitate with 1 ml EtOH -20ºC. Incubate 10 min. at -20ºC.
12. Incubate 5 min. at RT and spin 5 min. 13000 rpm.
13. Wash pellet with 70% EtOH and dry it completely.
14. Dissolve in 50 μl water + 0.5 μl RNaseA. Incubate 15 min. at 37ºC and store at -20ºC.
• Lysis buffer: 100 mM Tris-HCl pH 8, 50 mM EDTA, 1% SDS.