Abstract: Nucleic acids can be made available for amplification or other treatment after lysis by contacting the lysate with polyethyleneimine to form a precipitate with the nucleic acids. The nucleic acids are then released from the precipitate by contact with a strong base, and the released nucleic acids are kept in solution with an anionic phosphate ester surfactant. This method for preparing specimen samples is simple and quite rapid.

Abstract: A method and apparatus for forming in situ a new disposable tip for a dispensing probe within an analyzer, by feeding a continuous stock of tube through two die plates and severing the tube by relative motion of the die plates, while holding the cut portion in the dispensing probe temporarily inserted into one of the die plates. The tip is ejected from the probe in a direction opposite to the direction of insertion of the tube into the die plates and dispensing probe.

Abstract: A holder of slide test elements for use in an analyzer at a sample-dispensing station, the holder comprising two opposing holding surfaces for holding generally horizontally a slide test element at opposite side edges of the test element, and a tower extending above the holding surfaces for generally centering a dispensing tip above a held slide test element. The holder is improved in that one of the holding surfaces of the holder extends at least sufficiently for underneath a slide test element held by the holding surfaces to be disposed under an approximate center of the held test element, and includes a raised reference surface located under, and disposed for abutting against, an under-surface of the held slide test element, so that a held slide test element is prevented by the raised reference surface from warping downwardly away from a dispensing tip in the tower.

Abstract: The invention is directed to labeled drug hapten analogues comprising:(A) a label, of the type used in immunoassays, having an amine or sulfhydryl group;(B) a drug hapten nucleus selected from barbiturates or hydantoins and(C) a linking chain linking the 3-position of the drug hapten nucleus to the label through a carbonyl bridge.

Abstract: An aqueous wash solution is buffered to a pH of from about 5 to about 9 and contains at least about 1.5 weight percent of a compound comprising a lower alcohol sulfate anion having from 6 to 10 carbon atoms and an alkali metal or ammonium cation, such as sodium decyl sulfate. This wash solution is useful in a method for the determination of an immunological ligand, and is not prone to crystallization at lower temperatures. Particularly, it is useful for washing the immunological complex formed between the ligand and a receptor molecule therefor. Unreacted materials can be readily separated from the complex by the washing, particularly if the separation is carried out using a filtration membrane in a test device. A test kit for ligand determination comprises the wash solution as well as one or more receptors for the ligand, at least one of which is labeled for detection. This kit is particularly useful for measuring human chorionic gonadotropin (hCG) as an early indicator of pregnancy.

Abstract: A target nucleic acid can be detected in a semi-quantitative fashion by passing it over detection deposits in a test element. The detection deposits include particles affixed to the test element, some of which particles have capture probe attached thereto, and other particles having no capture probe. The deposits have varying amounts of capture probe so that the signal obtained when the target nucleic acid is captured thereon can be semi-quantitatively correlated to the amount of target nucleic acid in the specimen. This method of detection can be used in nucleic acid hybridization assays or following amplification methods, including polymerase chain reaction.

Abstract: One or more specific binding ligands can be detected with a competitive immunoassay which utilizes a water-soluble conjugate of ligand and reporter enzyme for each target ligand. Target ligand is allowed to compete for a first receptor with the conjugate. Uncomplexed conjugate is then contacted with an immobilized second receptor to form a reaction product which can be used to generate a detectable signal. This assay provides a direct correlation of the generated signal to the one or more target ligands.

Abstract: A centrifuge and method of operating it, wherein a patient sample tube is first spun while non-aligned with the centrifugal force to make use of the Boycott effect, and then while aligned with the centrifugal force to allow any gel present between the separated phases to properly seal. A latch is used to hold it in the non-aligned position until the latch is opened.

Abstract: Antibodies which are specific to a thermostable DNA polymerase can be used to reduce or eliminate the formation of non-specific products in polymerase chain reaction methods. These antibodies and other temperature sensitive inhibitors are effective to inhibit DNA polymerase enzymatic activity at a certain temperature T.sub.1 which is generally below about 85.degree. C. The inhibitors are irreversibly inactivated at temperature T.sub.2 which is generally above about 40.degree. C. T.sub.2 is also greater than T.sub.1. Such inhibitors can be supplied individually or in admixture with the DNA polymerase in a diagnostic test kit suitable for PCR.

Abstract: There is disclosed a closure mechanism for two reagent bottles in a bottle holder of an analyzer, using a shutter that slideably and frictionally engages the top surface of grommets at the mouth of the bottles. The shutter slides to either an open or closed position of the bottles, either both in lock-step or with one bottle open, the other closed, and both closed together. The shutter is driven by a cam and cam followers, either rotationally or linearly.

Abstract: Nucleic acids can be made available for amplification or other treatment after lysis by contacting the lysate with specific weakly basic polymers to form a precipitate with the nucleic acids at acidic pH. After removing non-precipitated materials, the pH is then made basic, thereby releasing the nucleic acids from the polymer. This method for preparing specimen samples is simple and quite rapid, and the released nucleic acids can be further treated in hybridization assays or amplification procedures. The weakly basic polymers are water-soluble and cationic at acidic pH, but neutral in charge at basic pH.

Abstract: An immunoassay method and analytical elements for detecting carbamazepine drugs, for example, in body fluids, is described.

Abstract: An array of tips is disclosed for multiple loading onto plural aspirators, wherein the array comprises columns of tips temporarily joined together within and between columns, at discontinuously spaced junctions. The array is moved along in tracks spaced so as to diverge when tip columns are to be broken out of the array. Each track ends in a step-down ledge that allows an aspirator to punch an engaged tip out of its column.

Abstract: A method for reducing interferent bias such as hemoglobin bias in immunoassays using dried slide test elements featuring peroxidase and leuco dye as the labeling mechanism.

Abstract: A conveyor and a method of providing a reaction cuvette using a conveyor, wherein a sensor is included to sense whether more than one cuvette is being conveyed. Because the cuvettes are received from a stack, one at a time, the sensor determines if two stacked cuvettes are present on the conveyor instead of one, by sensing the presence or absence of a cuvette projecting above the top of the desired cuvette.

Abstract: A heating assembly useful in apparatus for processing reaction cuvettes for replicating specified DNA sequences, such as those using PCR, having a heating element with a heat delivering surface for compressively contacting a pliable fluid-carrying compartment of a supported cuvette. The heat delivering surface has a defined passage sized to allow the detection compartment to be situated therein so that the compartment can be efficiently heated. Fluid flow through the compartment, however, is not interfered with during the heating process due to the presence of the defined passage. In addition, the heat delivering surface can be made from optically transparent materials so that visual detection within the processor can take place.

Abstract: Specific binding ligands can be detected with an assay which utilizes an immobilized receptor for the ligand, a reporter enzyme, an inhibitor antibody and an anti-inhibitor antibody. Both antibodies are specific for the reporter enzyme. 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 target specific binding ligand to the signal generated without the use of separation or wash steps.

Abstract: A highly sensitive homogeneous assay allows for quantitative detection of amplified nucleic acids. This detection is achieved during or after amplification with a high affinity fluorescent dye which is from the class of unsymmetrical cyanine dyes having at least two positive charges and a binding constant (K.sub.b) within the range of from about 1.times.10.sup.4 to about 5.times.10.sup.5 (molar.sup.-1). The reagents used for the assay can be contained in a kit designed for amplification such as by polymerase chain reaction.