Rare earth macrocyclic complexes and use thereof for reduction o

Details Rare earth macrocyclic complexes and use thereof for reduction o Rare earth macrocyclic complexes and use thereof for reduction o

1994-02-25

1995-10-10

Wu, Shean

Organic compounds -- part of the class 532-570 series

Organic compounds

Rare earth containing

534 16, 540460, 540465, 540470, C07F 500, C07D24500, C07D22500

Patent

active

054571847

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to macrocyclic rare earth complexes, to a method of reducing perturbations in a fluorescent assay using these complexes, and to their use for reducing the perturbations in the measuring medium of a fluorescent method of detecting and/or determining an analyte in a medium in which it may be present.
2. Description of the Prior Art
Immunoassays are widely used at the present time for the qualitative and quantitative analysis of compounds in biological fluids.
Among the techniques which exist, fluorimetric assays have become increasingly important.
In fact, they have a number of advantages, including the sensitivity and rapidity of the measurement, the stability and safety of the reagents labeled with fluorescent compounds, and the relatively low cost.
It is known that methods of detection which use fluorescence are intrinsically very sensitive and might permit lower detection limits than those achieved by immunoassays which use radiolabeled reagents, in particular when using modulatable laser light sources (I. Wieder, Immunofluorescence and related staining techniques, 1978, Elsevier).
A large number of fluorescent molecules which can be used as tracers in assays of this type have been described previously and include rare earth complexes possessing valuable properties.
The use of particular complexes, namely rare earth cryptates, is described in the patent applications EP 0 180 492, PCT/FR86/00269, EP 0 321 353 or
These rare earth cryptates have the advantage of being very stable in a saline protein medium, this property being particularly important in the case of homogeneous immunoassays.
The sensitivity of the measurement can nevertheless be greatly affected by difference types of perturbation resulting from the presence of various molecules in the measuring medium.
This problem is particularly acute in the case of assays in a serum medium in which numerous molecules are capable of interfering.
For example, the measured signal can be perturbed by the emission of molecules capable of being excited and of emitting at the same wavelengths as the molecule used as the tracer.
The time-resolved methods of measuring fluorescence enable this disadvantage to be partially overcome. The principle of these methods consists in measuring the fluorescence emitted by a tracer molecule having a relatively long emission lifetime, the measurement being delayed in time beyond the emission lifetime of the other molecules present.
In this case it is necessary to use fluorescent tracer molecules with a relatively long lifetime, such as rare earth chelates.
The sensitivity of the measurement can also be affected by interference from molecules in the medium capable of perturbing the variation in fluorescence resulting from the bonding between the analyte to be detected and the labeled biospecific reagent. The patent application EP 0 324 323 describes the use of a modulator which stabilizes the rare earth chelate bonded to the biospecific reagent, so that the measured fluorescence is a true function of the concentration of the analyte. The effect of this modulator is to prevent perturbation of the fluorescence of the rare earth chelate by the other molecules present in the medium. The measured variation in fluorescence is then a function of the antigen-antibody reaction only. The proposed modulators are macromolecules such as proteins and detergents, and have to be used in excess in the range from 0.1 to 10 g/l.
Nevertheless, none of these methods completely solves the problem of the perturbations due to the molecules present in the measuring medium. In fact, an important source limiting the sensitivity of the fluorescent measurement is the existence of quenching processes due to molecules present in the medium which are capable of inhibiting the fluorescence of the fluorescent molecule used as the marker in the assay. In the case of rare earth complexes, these processes can result from proximity electron transfer mechanisms, in which the inhibitor molecu

REFERENCES:
patent: 4761481 (1988-08-01), Hale et al.
patent: 4927923 (1990-05-01), Mathis et al.
patent: 5220012 (1993-06-01), Mathis et al.
patent: 5403928 (1995-04-01), Arrhennis
Helvetica Chimica Acta; vol. 74. No. 3. pp. 572-578, 1991.
Helvitica Chimica Acta; vol. 73. No. 1; pp. 106-111. 1990.
Helvitica Chimica Acta; vol. 73. No. 5. pp. 1149-1162, 1990.

Affiliated with

Also associated with

Rating

Rare earth macrocyclic complexes and use thereof for reduction o does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Rare earth macrocyclic complexes and use thereof for reduction o, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rare earth macrocyclic complexes and use thereof for reduction o will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2311028