Soak the gel for 15 min at 15–25 °C in several volumes of alkaline transfer buffer (0.4 M NaOH, 1 M NaCl) with constant gentle agitation. (ii) Change the solution and continue soaking for 20 min.

High-salt wash buffer: 500 mM NaCl, 0.1% SDS, 1% Triton X-100 ... pellet in 300 μl of nuclei lysis buffer by pipetting the solution up and down or by vortexing gently (keep the solution cold ...