Patent ID: 7018851

Claim:
A luminescent lanthanide chelate comprising a lanthanide ion and a chelating ligand of formula (I) wherein R 1 is selected from the group consisting of H, —COOH, —COO − , —CH 2 COOH and —CH 2 COO − ; G 1 is a group consisting of one or two moieties, each moiety being selected from the group consisting of ethynediyl (—C≡C—), ethenylene (—CH═CH—), phenylene, biphenylene, naphthylene, pyridylene, pyrazinylene, pyrunidinylene, pyridazinylene, furylene, thienylene, pyrrolylene, imidazolylene, pyrazolylene, thiazolylene, isothiazolylene, oxazolylene, isoxazolylene, furazanylene, 1,2,4-triazol-3,5-ylene and oxadiazolylene; G 2 is a group capable of being coupled to a biospecific binding reactant and is selected from the group consisting of amino, aminooxy, carboxyl, aldehyde or mercapto groups and activated forms made of them; Z is selected from the group consisting of carboxyalkyl amine {—N[(CH 2 ) n COOH] or —N[(CH 2 ) n COO − ]— and n=1, 2, 3, 4. 5, or 6}, ether (—O—), thioether (—S—), carbonyl (—CO—) and unsubstituted or substituted methyl (—CR 2 —) wherein group R 2 is selected from the group consisting of H, methyl, ethyl and carboxyalkyl{—CH 2 ) n COOH or —(CH 2 ) n COO − and n=1, 2, 3, 4. 5, or 6; and the lanthanide ion is a member selected from the group consisting of europium (III), terbium (III), dysprosium (III) and samarium(III).