ChIP-exo washing buffers composition

The washing buffers in ChIP-exo uses Tris-HCl to keep the pH constant, Triton X-100 to remove impurities, EDTA to chelate ions that will promote DNA degradation and different salts concentrations. All of them uses nuclease-free water as diluent.

Washing buffer I: 50 mM Tris-HCl (pH 7.5), 140 mM NaCl, 1% Triton X-100 and 1 mM EDTA.

Washing buffer II: 50 mM Tris-HCl (pH 7.5), 500 mM NaCl, 1% Triton X-100 and 1 mM EDTA.

Washing buffer III: 10 mM Tris-HCl (pH 8.0), 250 mM LiCl, 1% Triton X-100 and 1 mM EDTA.

Washing buffer IV (TE buffer): 10 mM Tris-HCl (pH 8.0) and 1 mM EDTA.