Good quality genomic DNA extraction

Published on Author Giorgio Gilestro

Solutions:

  • Solution A: [Tris HCI 0.1 M (pH 9.0), EDTA 0.1 M, SDS 1%] (keep at RT)
  • Phenol-Cloroform: [If done fresh: mix Phenol and Cloroform 1:1, shake, spin for 10 min at 4.000 rpm] (keep at 4°C)
  • KAc 8 M (keep at RT)
  • Isopropanol (keep at -20°C)
  • EtOH 70% (keep at -20°C)
  • TE (keep at 4°C)

Procedure:

  1. Place about 25 flies in an eppendorf tube, keep on ice
  2. Add 250 μl of solution A
  3. Homogenize the flies
  4. Incubate for 30 min at 70 °C
  5. Add 35μl of KAc
  6. Shake (no vortexing)
  7. Incubate for 30 min on ice
  8. Spin for 15 min at 13.000 rpm
  9. Move supernatant to a new tube (leave back any precipitate or interphase)
  10. Add 1 vol of Phenol-Chloroform to (9.) (ca. 250μl)
  11. Vortex
  12. Spin for 5 min at 13.000 rpm
  13. Repeat steps 9 to 12
  14. Move upper phase to a new tube
  15. Add 150μl of Isopropanol
  16. Shake
  17. Spin for 5 min at 10.000 rpm
  18. Suck off supernatant using a pipette, not vacuum to avoid losing pellet
  19. Wash the pellet with 1 ml 70 % EtOH
  20. Spin for 5 min at 13.000 rpm
  21. Dry the pellet 10 min under vacuum or on the bench for little longer. Do not over dry
  22. Resuspend the pellet in 100-200μl  of TE