Chemistry: analytical and immunological testing – Involving an insoluble carrier for immobilizing immunochemicals – Carrier is inorganic
Patent
1988-07-22
1993-10-12
Wityshyn, Michael G.
Chemistry: analytical and immunological testing
Involving an insoluble carrier for immobilizing immunochemicals
Carrier is inorganic
435 5, 435291, 422 73, 422 8205, 356337, G01N 33553
Patent
active
052524930
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a laser magnetic immunoassay method utilizing an antigen-antibody reaction and apparatus therefor. More particularly, the present invention relates to a laser magnetic immunoassay method which is capable of detecting a specific antibody or antigen in a very small amount of a specimen.
BACKGROUND ART
Development of immunoassay methods utilizing an antigen-antibody reaction is now being made on a global scale as an early detection method for new virus-based diseases such as AIDS and adult T-cell leukemia as well as various cancers. The methods are designed to detect an antibody or antigen itself utilizing the property of an antibody, which is prepared when virus or a like serving as an antigen has invaded into a living organism, to specifically react with the corresponding antigen (antigen-antibody reaction). As a micro-immunoassay method for this purpose, RIA (radioimmunoassay), EIA (enzyme-immunoassay), FIA (fluorescence-immunoassay), etc. have heretofore been used in practice. These methods use antigens or antibodies which are labeled with an isotope, an enzyme or a fluorescent substance in order to detect the presence of the corresponding antibodies or antigens, respectively, that react therewith.
Among them, RIA is to quantitatively determine the amount of the specimen which contributed to the antigen-antibody reaction by measuring the amount of the radio-activity of the isotope fixed for labeling. To date, only this method is capable of ultramicro measurement in the order of picogram. However, RIA needs special installment since it has to handle radioactive substances and there have heretofore been restrictions with respect to time and place for use and the like in view of the half-life period of the radioactive substances, disposal of wastes and the like. In addition, those methods which use enzymes or fluorescent substances are designed to confirm if the presence of antigen-antibody reactions and therefore they remain semi-quantitative and the detectability limit is in the order of nanogram. Therefore, it has been a demand for an immunoassay method which has a detection sensitivity in the same order as that of RIA but is free of restrictions when in use.
Examples of thus-far published methods in which a laser beam is used to detect the presence of antigen-antibody reaction include a method designed for detecting liver cancer, in which micro-particles of a plastic are provided with an antibody to AFP (alpha-faeto protein) and the change in the mass as the result of agglomeration between the plastic particles due to antigen-antibody reaction is monitored by the change in the scattering or transmission of a laser beam. Reportedly, the detection sensitivity of this method is 10.sup.-10 g, which is one hundred times higher than conventional laser methods, but still one hundred times less sensitive as that of RIA. Since the method utilizes the change in Brownian movement of antigens and antibodies in an aqueous solution, it is necessary to precisely control the temperature of the aqueous solution containing a specimen upon measurement, and the method is defective in that it is susceptible to influences from outside such as ambient temperature and vibration.
Also, there is an essential limitation in the improvement of the detection sensitivity of the conventional laser beam scattering measurement and a large amount of specimen is required since only a part of the aqueous solution in which the specimen is dispersed is irradiated. One approach proposed for obviating this defect is to use as a vessel capillary tubes having the same diameter as that of a laser beam in the laser beam scattering measurement with view to reducing time for measurement and minimizing the amount of a specimen used (U.S. Pat. No. 4,605,305). However, there is a problem in that the detection sensitivity is decreased due to disturbance of measurement by the scattered light from the walls of the capillary tubes.
Further, magnetic micro-particles are used in an attempt to facilitate the
REFERENCES:
patent: 849165 (1907-04-01), Schneider
patent: 3933997 (1976-01-01), Hersh et al.
patent: 3970518 (1976-07-01), Giaever
patent: 3990851 (1976-11-01), Gross et al.
patent: 4001583 (1977-01-01), Barrett
patent: 4018886 (1977-04-01), Giaever
patent: 4115535 (1978-09-01), Giaever
patent: 4152210 (1979-05-01), Robinson et al.
patent: 4171956 (1979-10-01), Uzgiris
patent: 4219335 (1980-08-01), Ebersole
patent: 4272510 (1981-06-01), Smith et al.
patent: 4313734 (1982-02-01), Leuvering
patent: 4446239 (1984-05-01), Tsuji et al.
patent: 4452773 (1984-06-01), Molday
patent: 4537861 (1985-08-01), Elings et al.
patent: 4605305 (1986-08-01), Lenoir et al.
patent: 4725140 (1988-02-01), Musha
patent: 4741619 (1988-05-01), Hummahries et al.
patent: 4762413 (1988-08-01), Namba et al.
patent: 4784954 (1988-11-01), Zimmermann
patent: 4859612 (1989-08-01), Cole et al.
patent: 4990075 (1991-02-01), Wogoman
Gruetzmacher et al. "Magnetic Immunoassay: A Heterogeneous Immunoassay Based on the Detection of Magnetic Particles." Clinical Chemistry, vol. 29, No. 6 (1983), p. 1252.
Fujiwara Koichi
Mizutani Hiroko
Mizutani Hiromichi
Noda Juichi
Beisner William H.
Nippon Telegraph and Telephone Corporation
Wityshyn Michael G.
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