Patent ID: 7238340

Claim:
A reagent comprising a targeting moiety covalently linked via a bivalent linking group to a metal chelator in which the metal chelator and the bivalent linking group together have the formula: wherein: R 1 and R 2 are each independently H, lower alkyl, hydroxyalkyl (C 2 –C 4 ), or alkoxyalkyl (C 2 –C 4 ); R 3 , R 4 , R 5 , and R 6 are independently H, substituted or unsubstituted lower alkyl or phenyl not comprising a thiol group, and one of R 3 , R 4 , R 5 , and R 6 is —L—(CR 2 ) n - where n is an integer from 1 to 6, and each R is independently H, lower alkyl, or substituted lower alkyl; R 7 and R 8 are each independently H, lower alkyl, lower hydroxyalkyl or lower alkoxyalkyl; X is —NH 2 , —NR 1 R 2 , or —NR 1 -Y, where Y is an amino acid, an amino acid amide, or a peptide of from 2 to about 20 amino acids; and L is the bivalent linking group.