Patent ID: 8324370

Claim:
A nucleic acid molecule comprising a first strand and a second strand, wherein said first strand comprises a first stretch that is complementary to a target nucleic acid, wherein said second strand comprises a second stretch that is the same length as said first stretch and is complementary to said first stretch, wherein said first strand and said second strand form a double-stranded structure comprising said first stretch and said second stretch, wherein said first stretch and said second stretch each comprises contiguous alternating ribonucleotides modified with an O-alkyl group, said alternating ribonucleotides modified with an O-alkyl group alternating with unmodified or modified ribonucleotides and wherein the ribonucleotides modified with an O-alkyl group of said first strand are shifted by one ribonucleotide relative to the ribonucleotides modified with an O-alky group of the second strand; wherein each stretch consists of at least 17 and fewer than 30 ribonucleotides.