RNA interference mediating small RNA molecules

A method of preparing a double-stranded RNA molecule, wherein each strand has a length of from 19–25 nucleotides, wherein said RNA molecule is capable of mediating the cleavage of a target mRNA in a mammal and at least one strand has a 3′ overhang of 1–3 nucleotides, comprising the steps of:

• a) selecting a target mammalian mRNA or target gene sequence,
• (b) synthesizing a first RNA strand having a length from 19–25 nucleotides, wherein said first RNA strand is complementary to contiguous nucleotides in said target mammalian mRNA or said target gene sequence,
• (c) synthesizing a second RNA strand having a length from 19–25 nucleotides, wherein said second RNA strand is complementary to 16–24 nucleotides from said first RNA strand, and
• (d) combining the synthesized RNA strands under conditions suitable to form a double stranded RNA molecule, wherein said double stranded RNA molecule consists of a single double stranded region of from 16–24 nucleotides in length and one or two single stranded 3′ overhang regions of 1–3 nucleotides in length each.

A method of preparing a double-stranded RNA molecule, wherein each strand has a length of from 19–23 nucleotides, wherein said RNA molecule is capable of mediating the cleavage of a target mRNA in a mammal and at least one strand has a 3 overhang of 1–3 nucleotides, comprising the steps of:

• a) selecting a target mammalian mRNA or target gene sequence,
• (b) synthesizing a first RNA strand having a length from 19–23 nucleotides, wherein said first RNA strand is complementary to contiguous nucleotides in said target mammalian mRNA or said target gene sequence,
• (c) synthesizing a second RNA strand having a length from 19–23 nucleotides, wherein said second RNA strand is complementary to 16–22 nucleotides from said first RNA strand, and
• (d) combining the synthesized RNA strands under conditions suitable to form a double stranded RNA molecule, wherein said double stranded RNA molecule consists of a single double stranded region of from 16–22 nucleotides in length and one or two single stranded 3′ overhang regions of 1–3 nucleotides in length each.

A method of preparing a double-stranded RNA molecule, wherein each strand has a length of from 19–25 nucleotides, wherein said RNA molecule is capable of mediating the cleavage of a target mRNA in a mammal and at least one strand has a 3′ overhang of 1–3 nucleotides, comprising the steps of:

• a) selecting a target mammalian mRNA or target gene sequence,
• (b) synthesizing a first RNA strand having a length from 19–25 nucleotides, wherein said first RNA strand is complementary to contiguous nucleotides in said target mammalian mRNA or said target gene sequence,
• (c) synthesizing a second RNA strand having a length from 19–25 nucleotides, wherein said second RNA strand is complementary to 16–24 nucleotides from said first RNA strand, and
• (d) combining the synthesized RNA strands under conditions suitable to form a double stranded RNA molecule, wherein said double stranded RNA molecule is 16–24 nucleotides in length and the only single stranded regions in said RNA molecule are one or two single stranded 3′ overhang regions of 1–3 nucleotides in length each.

A method of preparing a double-stranded RNA molecule, wherein each strand has a length of from 19–23 nucleotides, wherein said RNA molecule is capable of mediating the cleavage of a target mRNA in a mammal and at least one strand has a 3′ overhang of 1–3 nucleotides, comprising the steps of:

• (a) selecting a target mammalian mRNA or target gene sequence,
• (b) synthesizing a first RNA strand having a length from 19–23 nucleotides, wherein said first RNA strand is complementary to contiguous nucleotides in said target mammalian mRNA or said target gene sequence,
• (c) synthesizing a second RNA strand having a length from 19–23 nucleotides, wherein said second RNA strand is complementary to 16–22 nucleotides from said first RNA strand, and
• (d) combining the synthesized RNA strands under conditions suitable to form a double stranded RNA molecule, wherein said double stranded RNA molecule is 6–22 nucleotides in length and the only single stranded regions in said RNA molecule are one or two single stranded 3′ overhang regions of 1–3 nucleotides in length each.