Abstract: A cuvette and a method of use prevent nucleic acid amplified by PCR technology from being released to the atmosphere, while still proceeding to a detection step to determine whether or not the nucleic acid is present. Detection reagents are either pre-incorporated into compartments in the cuvette or added after amplification. In the latter case, a check valve prevents amplified nucleic acid from being released. Transfer of liquids between compartments is achieved via the use of flexible compartment walls and an external pressure source, or via pistons that are part of the cuvette and operate on the compartments as a piston within a piston chamber.

Abstract: Nucleic acids can be amplified and detected using a very rapid polymerase chain reaction procedure. This procedure includes a series of steps which have critically defined temperature and time parameters. Each polymerase chain reaction cycle requires generally less than about two minutes, and in most cases less than 90 seconds. At least 5 units/100 &mgr;l of solution of thermostable DNA polymerase are used, and other preferred levels of primer concentrations facilitate the quick cycling in the amplification. In preferred embodiments, only two temperatures are used in the amplification.

Abstract: An analytical element can be used to sensitively and rapidly detect a wide variety of specific binding ligands in either a competitive or sandwich assay format. The assays are carried out using a vanadium bromoperoxidase-labeled immunoreactant and a chemiluminescent signal-providing wash composition which comprises a 2,3-dihydro-1,4-phthalazinedione derivative; a halogen, pseudohalogen, halogen-providing source or pseudohalogen-providing source; and a peroxide or a peroxide-generating reagent composition.

Abstract: The present invention relates to a method for amplifying and detecting a target nucleic acid. The method comprising contacting a sample suspected of containing the target nucleic acid with a thermostable DNA polymerase and two primers that are substantially complementary to the target nucleic acid, under conditions such that the target nucleic acid is amplified. The amplified target nucleic acids are then denatured to form single stranded nucleic acids. Following amplification, the sample is subject to a pre-detection incubation step. The sample is incubated for between 1 second and 30 minutes at between 95° C. and 120° C. to inactivate said polymerization agent. Finally, the presence or absence of the amplified target nucleic acids is determined. Preferably, amplification, incubation and detection are carried out in a closed reaction vessel.

Abstract: An aqueous composition containing primers for opposing strands of two or more target nucleic acids can be used in polymerase chain reaction to provide simultaneously rapid and efficient amplification and detection of those nucleic acids. The primers for each target DNA differ in length by no more than 5 nucleotides and have a Tm within the range of from about 65 to about 74° C., while the Tm's are within about 5° C. of each other. Such compositions are useful in diagnostic test kits and methods for amplification and detection of multiple nucleic acids, or in “multiplexing”, using multiple capture probes. All of the capture probes have Tm's which are greater than 50° C. and are within 15° C. of each other.

Abstract: The Thermus aquaticus gene encoding a thermostable DNA polymerase (Taq Pol) is altered in the N-terminus-encoding region to provide mutant genes with improved expression in E. coli.

Abstract: Dimeric inhibin concentration can be used in the determination of the risk of a women carrying an unborn child affected by chromosomal abnormalities, e.g. Downs Syndrome. A method for antenatal screening for chromosomal abnormalities is carried out by measuring body fluid taken from a pregnant woman for the level of at least one marker or precursor or metabolite of the marker together with the gestational age of the woman are compared with reference values taken from women carrying fetuses with chromosomal abnormalities and/or women carrying normal fetuses, using dimeric inhibin as a marker. A second marker is the free beta subunit of human chorion gonadotropin. An apparatus for carrying out the method described comprises a computer with a means for comparing the values described.

Abstract: A method for antenatal screening for chromosomal abnormalities in which maternal blood from a pregnant woman is measured for levels of free beta hCG and at least a second serum marker and/or precursors and metabolites of these markers and the measured levels of these markers together with the gestational age of the pregnant woman are compared to reference values at various gestational ages of the levels for free beta hCG and the second serum marker in (a) pregnant women carrying foetuses having the abnormalitie(s) subject to the screen and (b) pregnant women carrying normal foetuses, the comparison being indicative of the risk of the pregnant woman carrying a foetus with an abnormality subject to the screen characterised in that the second serum marker is pregnancy associated plasma protein A (PAPPA) and the screen is carried out by the end of the thirteenth (13th) completed week of pregnancy.

Abstract: A reaction vessel for confined amplification and detection of nucleic acid material. The vessel features a plurality of adjacent chambers, each chamber comprising a front wall, a back wall, two side walls, and a bottom wall, the front and back walls terminating in an upper opening at a top edge of said front and back walls, a side wall of each chamber comprising a side wall in common with an adjacent chamber so as to integrally connect the chambers side-by-side; the front wall of each chamber including a liquid access port spanning all of the chambers below the top edge, the common side walls terminating at the port; and a movable elastomeric plug mounted within the upper opening above the port, shaped to block the port of each of the chambers and to stopper each the chamber when moved below the top edge, the plug spanning across all of the chambers in the vessel so as to close off the port simultaneously for all of the chambers when moved below the top edge.

Abstract: A dry analytical element has been prepared for the assay of prostatic acid phosphatase at a pH of from about 3 to about 6.5. The element can be a single porous spreading zone or a multilayer structure. Within the element is a relatively nonhygroscopic aromatic phosphate substrate for the analyte which produces a phenol reaction product. This product is reacted with a diazonium or tetrazolium salt, also in the element, to produce a chromophore for detection. A buffer in the element maintains it at the proper pH during the assay.

Abstract: A method of preventing false detection of signal due to splashing of reagent liquid used to produce such signal, when dispensing at least one such liquid from a metering tip into a second liquid, comprising the steps of: a) positioning the metering tip a predetermined distance above the upper level of the second liquid prior to dispensing the one liquid; andb) while maintaining the distance throughout the dispensing of the one liquid, dispensing the one liquid;wherein the predetermined distance is between about 1.0 mm and about 2.0 mm so that splashing during dispensing is reduced.

Abstract: A carrier for surface plasmon resonance is prepared by coating a silver layer on the carrier surface, followed by heating the material for a time sufficient to anneal it.

Abstract: Apparatus for and a method of detection of light transmitted or reflected from a test object using any one of plural filters each with a unique center wavelength. To prevent chromatic aberration in non-collimated light passed through the filters, the thickness of each filter is unique, depending on its center wavelength.

Abstract: The present invention relates to a dry immunoassay analytical element for assaying a ligand, comprising a support bearing: (a) a label zone comprising an enzyme labeled ligand or an enzyme labeled receptor; (b) a spreading zone; (c) a receptor zone comprising a fixed concentration of an immobilized receptor for the ligand; and (d) a gravure zone comprising a diaryl telluride. A prefered embodiment of the present invention further comprises a vanadyl salt. The present invention further relates to a method for performing an assay using an element as described above.

Abstract: Specific binding ligands can be detected with an assay which utilizes an immobilized receptor for the ligand, an immobilized reporter enzyme, an inhibitor antibody and a a water-soluble conjugate of the ligand and an anti-inhibitor antibody. Both antibodies are specific for the reporter enzyme, but the antibodies affect enzymatic activity differently. The inhibitor antibody effectively shuts down the activity of the reporter enzyme when it is complexed thereto. The anti-inhibitor antibody binds to the reporter enzyme, does not affect the enzymatic activity, but prevents the binding of the inhibitor enzyme. This assay provides a direct correlation of the generated signal to the target specific binding ligand.

Abstract: A method and fluorimeter for flashing a target at several different levels for detection of fluorescence by a PMT without blinding the PMT at the highest level. Two lamps are provided each of which is powered to flash at two different levels that are staged in energy from the lowest of four to the highest of four levels, and a shutter is provided to close off the PMT from exposure when an acceptable, detectable level of fluorescence is detected by the PMT.

Abstract: Nucleic acids can be amplified and detected using an element which has a sealable support on which is disposed a nucleic acid reagent composition. The composition is a mixture of a nucleic acid reagent composed of polymeric particles to which an oligonucleotide is covalently attached. The particles are prepared from a first polymer having a glass transition temperature of at least about 70.degree. C. and have an average diameter of from about 0.1 to about 3 micrometers. The reagent is adhered to the support using a water insoluble adhesive comprising a second polymer which has a glass transition temperature which is at least about 30.degree. C. less than the glass transition temperature of the first polymer. The adhesive is present in the composition at from about 1 to about 20 dry weight percent. The method provides high sensitivity and low background in the assay of nucleic acids, preferably using polymerase chain reaction.

Abstract: Apparatus and method for detecting patient sample quality, and/or analytes, in the tip used to aspirate the patient sample liquid and then dispense it onto a slide test element. Spectrophotometric analysis is done on the liquid while still in the tip, by scanning the tip for transmittance in a light-tight enclosure, using NIR and adjacent visible radiation, and detecting the absorbence spectra of the liquid. Much smaller liquid volumes, and no through-the-label detection, are required, compared to doing the scanning of the liquid in a primary patient collection container.

Abstract: A flexible container containing pre-deposited reagents, comprising a plurality of temporarily sealed, breakable compartments dispersed in the container, each compartment containing a reagent useful for immuno-assaying, and each compartment comprising opposed confining walls at least one of which is sufficiently flexible as to allow the compartment to be compressed in the presence of an adequate external force, external outlets in the container for the contents of said compartments, passageways extending from each of the compartments to the outlets, each of the outlets terminating in a platform that supports a drop of at least 10 .mu.L as a pendant drop, the platforms of at least two of the outlets being adjacent so as to form between them an exterior angle with respect to each other sufficient to cause drops pendant therefrom to substantially uniformly intermix.

Abstract: A method for antenatal screening for chromosomal and other abnormalities in an unborn child is determined by measuring the gestational age discrepancy of the pregnant mother. This data is determined (a) by reference to the last menstrual period, and (b) a biometric measurement of the fetus. The difference between the ages as determined using (a) and (b) is calculated. This calculated difference is then examined using reference data to determine fetal abnormalities. These data can also be used with assay of maternal fluids for various pregnancy markers.