We introduce skew cyclic codes over the finite ring F2 +uF2 +vF2 +wF2 +uvF2 +uwF2 +vwF2 +uvwF2, where u 2 = 0, v 2 = v, w 2 = w, uv = vu, uw = wu, vw = wv and use them to construct reversible DNA codes. The 4-mers are matched with the elements of this ring. The reversibility problem for DNA 4-bases is solved and some examples are provided.