Patent ID: 7759469

Claim:
A compound having the formula wherein A is selected from the group consisting of H, phosphate, triphosphate, a protecting group, and a chain of nucleotide tide residues, B is selected from the group consisting of H, a phosphoramidite group, an H-phosphonate, a solid support, and a chain of nucleotide residues, R is selected from the group consisting of H, F, OH, O-alkyl, O-alkenyl, O-alkinyl, and an O-protective group one of W 1 and W 2 is C—NO 2 , and the other of W 1 and W 2 is CH or N, one of X 1 , X 2 , X 3 , and X 4 is selected from the group consisting of a reactive group, a protected reactive group, a linker with a reactive group, a linker with a protected reactive group, a signal entity, a protected signal entity, a linker with a signal entity, and a linker with a protected signal entity, and the remaining three of X 1 , X 2 , X 3 , and X 4 are each H.