Chemistry: analytical and immunological testing – Rate of reaction determination
Patent
1987-10-09
1989-09-19
Marcus, Michael S.
Chemistry: analytical and immunological testing
Rate of reaction determination
356414, 356417, 356418, 422 57, 422 58, 422 68, 435 7, 436164, 436805, G01N 3106, G01N 3348
Patent
active
RE0330647
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to the use of waveguide for the determination of the concentration of a species (or analyte) in solution in a liquid by measuring the rate (concentration dependent) for its combination with or disassociation from a specific reactant thereto, e.g. a conjugate moiety in a complexation reaction. More specifically, the invention concerns a method for determining an analyte in solution in which a layer of analyte-reactant product is formed at the surface of a waveguide into which a light signal is injected and carrying a totally and multiply reflected electromagnetic wave signal and in which the layer changes the optical properties thereof so as to modify said signal, said modification being measured and used for said determination. Thus, the invention applies to a variety of chemical and biological systems and, particularly well, to the determination of bioactive molecules in low concentration by immunoassay type reactions, i.e. reactions based on the formation of complexes by the addition of antibody (AB) to antigen (AG) molecules or vice-versa.
BACKGROUND OF THE INVENTION
Many methods already exist in the field for achieving the above mentioned determination based on the classical techniques of biochemistry. For instance, chemical reactions can be used to detect a given analyte in a number of different ways. Classical systems include titration or reaction with a specific reagent that gives a colored product or precipitate. The requirement for this detection system is that the reagent is in equivalence or in excess, so that the product can be measured by conventional photometry, turbidimetry, colorimetry, etc. The measuring system is chosen according to the magnitude of the signal to be measured. At very low analyte concentrations detection becomes difficult and greater discrimination can be obtained, for example, by concentrating the reaction product locally e.g. by solvent extraction, centrifugation, etc. which may become tedious and costly. However, the above disadvantage was strongly reduced when a practical system for the measurement of biochemical analytes in extremely low concentrations was made available in 1960. This microanalytical system (radioimmunoassay) took advantage of the characteristics of biological systems for molecular recognition (antigen-antibody reactions) and the extreme sensitivity of radioactive measurements (radioactive isotope labelling). An essential feature of this breakthrough was the concept of limited reagent assay with the tracer label used to measure the distribution of the analyte to be measured between the reagent-bound and the free moieties (see for example: Review Paper "The theoretical aspects of saturation analysis" R. P. Ekins in "In vitro procedures with radioisotopes in medicine", International Atomic Energy Agency, June 1970). Although immunoassays were first described as limited reagent assays, equally practical systems were later described for reagent excess methods (see MILES et al. Biochem. J. 108, 611 (1968).
In addition to volumetric and gravimetric analysis, the present methods thus involve highly sensitive methods such as colorimetry, spectroscopy and radio active measurements. However, many of such techniques are now becoming obsolete as they are tedious, require a relatively large quantity of analyte to be accurate, are based on hard to prepare and difficult to store reagents or require expensive and cumbersome equipment and highly skilled operators. Thus, there is a trend now to develop more subtle methods, which require lesser quantities of reagents and which can be performed safely, quickly and accurately by moderately skilled personnel. Among such methods which have been disclosed lately, some involve the use of optical waveguides including the reactant. For analysis, the waveguide is contacted with the analyte in solution whereby a reaction with the reactant on the wave guide occurs with the consequence that the optical properties of the latter are modified. The measurement of such modificatio
REFERENCES:
patent: 4050895 (1977-09-01), Hardy et al.
Holm et al; Internal-reflection Spectroscopy; Laser Focus, vol. 15, No. 8, Aug. '79 pp. 60-65.
Muller; Spectroscopy with the Evanescent Wave in the Visable Region of the Spectrum; American Chem. Soc. '79, pp. 239-262.
Harrick et al; Multiple Internal Reflection Florescence Spectrometry; Analytical Chem vol. 45, No. 4, Apr. '73, pp. 687-691.
Harrick; Internal Reflection Spectroscopy; Interscience Pub. New York: 1967 pp. 13-65.
"Kinetics of Antibody-Hapten Interaction", Molecular Biology, (1977) pp. 306-338.
"Experimental Methods in Biophysical Chemistry" Ed. Claude Nicolou, J. Wiley and Sons, New York, 1973 pp. 613-647.
Handbook of Biochemistry, Chemical Rubber Company Press, pp. C36-C39.
Gerhard J. Muller, A.C.S. Symposium Series (1979) 239-262.
Carter Timothy J. N.
Dahne Claus
Place John F.
Dubno Herbert
Marcus Michael S.
Prutec Limited
LandOfFree
Method for the determination of species in solution with an opti does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for the determination of species in solution with an opti, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for the determination of species in solution with an opti will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-359296