Chemical apparatus and process disinfecting – deodorizing – preser – Analyzer – structured indicator – or manipulative laboratory... – Means for analyzing liquid or solid sample
Reexamination Certificate
2000-08-03
2001-12-18
Riley, Jezia (Department: 1656)
Chemical apparatus and process disinfecting, deodorizing, preser
Analyzer, structured indicator, or manipulative laboratory...
Means for analyzing liquid or solid sample
C435S006120, C435S091100, C435S091200, C536S022100, C536S024300, C536S025300
Reexamination Certificate
active
06331275
ABSTRACT:
1. INTRODUCTION
The present invention relates to the field of diagnostics and the detection of small quantities of substances in fluids. More specifically, the invention relates to a cleavable signal element, particularly a cleavable reflective signal element, for use in assay devices. The assay devices employing such signal elements are, in preferred embodiments of the invention, adapted for detection using standard laser-based detection systems, such as CD-ROM readers, DVD readers, and the like. The invention further includes analytical methods for detecting analytes using the assay devices of the present invention. The signalling element, assay devices and assay methods of the present invention are useful both for the detection of a large number of different analytes in a test sample and the detection of a single analyte in a large number of samples.
2. BACKGROUND OF THE INVENTION
2.1 Small Scale Clinical Assays
Until recently, most clinical diagnostic assays for the detection of small quantities of analytes in fluids have been conducted as individual tests; that is, as single tests conducted upon single samples to detect individual analytes. More recently, efficiency and economy have been obtained by designing apparatus for multi-sample preparation and automated reagent addition, and by designing apparatus for rapid analysis of large numbers of test samples, either in parallel or in rapid serial procession. Often, such automated reagent preparation devices and automated multiplex analyzers are integrated into a single apparatus.
Large clinical laboratory analyzers of this type can accurately perform hundreds of assays automatically, or semi-automatically, in one hour. However, these analyzers are expensive and only centralized laboratories and large hospitals can afford them. Such centralization necessitates sample transport, and often precludes urgent or emergent analysis of time-critical samples.
Thus, there exists a strong need for simplified clinical assays that will both reduce the cost of such dedicated analyzers and further their distribution. The limit of such effort is the design of clinical tests suitable for use at the patient bedside or in the patient's home without dedicated detectors. Blood glucose and pregnancy tests are well known examples.
Although useful tests of this sort have been offered for many years, a major breakthrough was the introduction of solid phase immunoassays and other strip tests since approximately 1980. Most notable are Advance® test (Johnson & Johnson), RAMP™ hCG assay (Monoclonal Antibodies, Inc.), Clear Blue Easy™ (Unipath Ltd.) and ICON (Hybritech).
Clear Blue Easy™ has all reagents in a laminated membrane and uses conjugated colored latex microbeads as the signal reagent. It uses a capillary migration immunoconcentration format. The ICON is a dual monoclonal sandwich immunoconcentration assay. This assay has been rendered quantitative through the use of a small reflectance instrument. Otherwise, all these methods are only qualitative.
Migration distance can be used as a basis for quantitative assays. Commercially available are Quantab™ (Environmental Test Systems), AccuLevel® (Syva), AccuMeter® (ChemTrak), Clinimeter™ (Crystal Diagnostics) and Q.E.D.™ (Enzymatics). One of the newest is a thermometer-type assay device (Ertinghausen G., U.S. Pat. No. 5,087,556) that is not yet commercially available. These systems can be used to assay general chemistry analytes, such as cholesterol, as well as blood levels of therapeutic drugs.
One disadvantage, however, of each of these formats is that only one, or a very limited number, of assays can conveniently be performed simultaneously.
To fill the gap between massive analyzers and strips, some small instruments have been developed. The most notable is Eclipse ICA™ (Biotope, Inc.). This device is a bench-top, random-access, automated centrifugal immunoassay and chemistry system. Patient samples are pipetted into cassettes that are placed into a rotor. Sixteen tests can be run in approximately 17 minutes. The results are measured by UV/Visual spectrometry or by fluorometry. Four different types of cassette are needed. Each cassette has a relatively complicated structure.
Despite these developments, there still exists a need for a simple device that can easily be used for multiple quantitative assays, and preferably requiring no specialized detector instrumentation.
2.2 Spatially-Addressable Probe Arrays
Recently, spatially addressable arrays of different biomaterials have been fabricated on solid supports. These probe arrays permit the simultaneous analysis of a large number of analytes. Example are arrays of oligonucleotides or peptides that are fixed to a solid support and that capture complementary analytes. One such system is described by Fodor et.al., Nature, Vol. 364, Aug. 5, 1993. Short oligonucleotide probes attached to a solid support bind complementary sequences contained in longer strands of DNA in liquid sample; the sequence of the sample nucleic acids is then calculated by computer based on the hybridization data so collected.
In the assay system described by Fodor et al., the array is inverted on a temperature regulated flow cell against a reservoir containing the tagged target molecules. In order to distinguish the surface bound molecules, the system requires an extremely sensitive detector.
Accordingly, there remains a need for an economical system to fabricate spatially addressable probe arrays in a simplified format that provides both for ready detection and the ability to assay for large numbers of test substances (i.e. analytes) in a fluid test sample in a single step, or a minimum number of steps, or assay for a single test substance or analyte in a large number of fluid test samples.
2.3 Spatially Addressable Laser-Based Detection Systems
Several devices for consumer electronic use permit spatially addressable detection of digital information. In particular, several formats have been developed based on the information recording potential of differential reflectance and transmittance.
In conventional audio or CD-ROM compact disks, digital information—or digitally encoded analog information—is encoded on a circular plastic disk by means of indentations in the disk. Typically, such indentations are on the order of one-eighth to one-quarter of the wavelength of the incident beam of a laser that is used to read the information present on the disk. The indentations on the disk cause destructive interference within the reflected beam, which corresponds to a bit having a “zero” value. The flat areas of the disk reflect the laser light back to a detector and the detector gives a value of “one” to the corresponding bit.
In another convention, a change of intensity of a reflected light gets a value of one while a constant intensity corresponds to zero.
Since the indentations have been formed in the disk in a regular pattern from a master copy containing a pre-determined distribution of bits of “zero” and bits of “one”, the resultant signal received by the detector is able to be processed to reproduce the same information that was encoded in the master disk.
The standard compact disk is formed from a 12 cm polycarbonate substrate, a reflective metalized layer, and a protective lacquer coating. The format of current CDs and CD-ROMs is described by the ISO 9660 industry standard, incorporated herein by reference.
The polycarbonate substrate is optical-quality clear polycarbonate. In a standard pressed, or mass-replicated CD, the data layer is part of the polycarbonate substrate, and the data are impressed in the form of a series of pits by a stamper during the injection molding process. During this process, molten polycarbonate is injected into a mold, usually under high pressure, and then cooled so that the polycarbonate takes on the shape of the mirror image of the mold, or “stamper” or “stamp”; pits that represent the binary data on a disc's substrate are therefore created in and maintained by the polycarbonate substrate as a mirror image of the pits of the stamper created
Burstein Technologies, Inc.
Riley Jezia
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