RNase H induced cleavage pattern of RNA–(2′-OMe)RNA hybrid in the presence of the CeNA antisense oligonucleotide: samples were taken at different time intervals (5, 10, 15, 20, 30 and 60 min); Arrows: o, full substrate; a, cleavage between rU1 and rU2; c, cleavage between rU3 and rU4.