Patent ID: 6864049

Claim:
A hybridisation complex which comprises a first nucleic acid molecule hybridized with a second nucleic acid molecule, wherein the complex comprises: at least one modified C—G base pair, wherein at least one C or G base contained in the sequence of the first and/or second nucleic acid molecule, or at least one C and G contained in the sequence of the first or second nucleic acid molecule, is a modified base, such that the difference between the melting temperature of: i.) the complex and ii) the complex wherein in place of the modified base pair is a naturally-occurring A—T base pair is less than the difference between the melting temperature of: i) the complex wherein in the place of the modified base pair is a naturally-occurring C—G base pair and ii) the complex wherein in the place of the modified base pair is a naturally-occurring A—T/U base pair; or wherein the complex comprises: at least one modified A—T/U base pair, wherein at least one A or T/U base contained in the sequence of the first and/or second nucleic acid molecule, or at least one A and T/U base contained in the sequence of the first or second nucleic acid molecule, is a modified base, such that the difference between the melting temperature of: i.) the complex wherein in place of the modified base pair is a naturally-occurring C—G base pair and ii) the complex is less than the difference between the melting temperature of: i) the complex wherein in the place of the modified base pair is a naturally-occurring C—G base pair and ii) the complex wherein in the place of the modified base pair is a naturally-occurring A—T/U base pair; or wherein the complex comprises: at least one modified C—G base pair and at least one modified A—T/U base pair, wherein at least one C and/or G base and at least one A and/or T/U base contained in the sequence of the first or second nucleic acid molecule is a modified base, or wherein at least one A or T/U base and at least one C or G base contained in the sequence of the first and second nucleic acid molecule is a modified base, wherein the melting temperature of the complex is between: (i) the melting temperature of the complex wherein in place of the modified C—G base pair and modified A—T/U base pair are naturally-occurring C—G base pairs, and ii) the melting temperature of the complex wherein in place of the modified C—G base pair and modified A—T/U base pair are naturally-occurring A—T/U base pairs.