Patent ID: 7267994

Claim:
A method for detecting oxidation patterns of an oxidized biomolecule, said method comprising: (a) contacting a biological sample suspected of containing an oxidized biomolecule with a tag moiety comprising a macrocyclic chelating agent complexed to a metal ion, wherein the macrocyclic chelating agent has the formula (Ia): wherein each of L 1 , L 2 , L 3 and L 4 are linking groups independently selected from C 2-5 alkylene which is optionally substituted with one to three substituents selected from the group consisting of substituted and unsubstituted alkyl, substituted and unsubstituted heteroalkyl and substituted and unsubstituted aryl; each of R N1 , R N2 , R N3 and R N4 are independently selected from the group consisting of substituted and unsubstituted alkyl, substituted and unsubstituted heteroalkyl and substituted and unsubstituted aryl; wherein at least one of L 1 , L 2 , L 3 , L 4 , R N1 , R N2 , R N3 and R N4 comprises a functional group that forms a covalent linkage at an oxidized site on said oxidized biomolecule, thereby forming an adduct between said oxidized biomolecule and said tag moiety; (b) contacting said adduct with an affinity medium comprising a first binding moiety that binds said tag moiety; (c) eluting said adduct from said affinity medium, thereby forming a solution comprising said adduct; and (d) detecting the adduct by detecting the weight of the adduct comprising the metal ion in the tag moiety of step (c), thereby detecting the oxidation pattern of the biomolecule.