Chelate labelling

Simple DTPA chelates labeled with 90Y are not sufficiently stable in vivo. This instability leads to accretion of the metal ion in bone such unwanted accumulation results in undesirable irradiation of the bone marrow.90... 

Certain bifunctional metal chelating agents have been used to investigate protein interactions by virtue of their ability to generate reactive oxygen species that affects protein structure in the immediate vicinity of their modification site. The following sections discuss two applications of such chelate labels, one of which cleaves peptide bonds while the other one causes covalent crosslinks to occur between interacting protein structures. 

Diamandis, E.P., and Christopoulos, T.K. (1990) Europium chelate labels in time-resolved fluorescence immunoassays and DNA hybridization assays (Review). Anal. Chem. 62, 1149-1157. 

E. P. Diamandis and T. K. Christopoulos, Europium Chelate Labels in Time-Resolved Fluorescence Immunoassays and DNA Hybridization Assays, Anal. Chem. 1990, 62, 1149A. 

Wortberg, M., C. Middendorf, A. Katerkamp, T. Rump, J. Krause, and K. Cammann (1994). Flow-injection immunosensor for triazine herbicides using Eu(III) chelate label flourescence detection. Anal. Chim. Acta, 289 177-186. 

Pbimpbivong, S., Kolchens, S., Edmison, P.L., and Saavedra, S. (1995) Time resolved, total internal reflection fluorescence microscopy of cultured cells using a Tb chelate label. Analytica Chimica, 307, 403 17. 

Rainsbury, R.M. Westwood, J.H. Coombes, R.C. Localization of metastatic breast carcinoma by monoclonal antibody chelate labeled with in-111. Lancet 1983, 1, 934—938. 

The pulsed-source (time-resolved) method, then effects spectroscopic separation of the emission of several fluorescing species by taking advantage of differences in their decay times rather than their fluorescence intensities. This means that several overlapping fluorescences, such as those of free and antibody-bound ligand can be quantified simultaneously. Lanthanide chelate-labeled antibodies, which have long lifetimes (in the 1 = ms to 1 = ps range) form the basis of a time-resolved FIA, for which instrumentation is commercially available. 

The efficient use of time resolved fluorometry is based on the use of lanthanide chelate labels with unique fluorescence properties (6-8, 13-15). The chelates can be clearly divided into those designated non-fluorescent chelates for dissociation chemistry (i.e. DELFIA chemistries) and the highly stable fluorescent chelates. 

Mikola H, Takalo H, and Hemmila I. (1995) Synthesis and Properties of luminescent lanthanide chelate labels and labelled antigens for homogeneous immunoassays. Bioconj. Chem. 6 (3) 235-241. 

The Turku University and PerkinElmer group reported a new method named TruPoint -PCR (Nurmi et al., 2002). They introduced quencher probes, which have a 3 -quencher labeling, in addition to detection probes, which have a 5 -lanthanide-chelate labeling. The quencher probes are designed to be complementary to the detection probes with their values below the PCR annealing temperature (here is the temperature at which 50% of DNA mole-... 

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