Protocol for DNA Isolation from Mouse Tissue

  1. Excise ~0.5 cm of the mouse tail tip and place in a 1.5ml eppendorf tube.
  2. Add 400 µl of tissue digestion buffer (10 mM Tris, pH 7.5, 10 mM EDTA, 100 mM NaCl, 0.5% SDS) containing 50 µg/ml Proteinase K (Roche Molecular)
  3. Incubate overnight at 55°C with gentle shaking.
  4. Allow the tubes to cool to room temperature and flash spin to remove the solutions from the tube lid.
  5. Add 400 µl of phenol/chloroform solution (1:1).
  6. Close the tubes and mix vigorously by shaking or inverting the tubes (do not vortex).
  7. Spin in a microfuge at maximum speed for 5 minutes.
  8. Transfer the top aqueous phase to a new 1.5 ml eppendorf tube. Use a large orifice pipetman tip to transfer.
  9. Precipitate the DNA by adding 2 volumes of absolute ethanol and shake vigorously until the precipitate is visible.
  10. Spin in a microfuge at maximum speed for 4 minutes. Decant the supernatant.
  11. Wash the pellet with 200 µl of 70% ethanol.
  12. Spin in a microfuge at maximum speed for 1 minute. Decant all of the supernatant.
  13. Air dry the tubes.
  14. Resuspend the DNA pellet in 200 µl TE buffer (10 mM Tris, 1 mM EDTA). Resuspension of the DNA can be aided by incubating the tubes at 37°C for several hours.