Abstract:
A method and apparatus determines the analyte content of a sample by generating first and second input signals and directing the input signals to the sample. The input signals differ in wavelength by at least 3 nanometers. Due to the interaction between the input signals and the sample, first and second output signals are generated. Each output signal comprises a resonant signal whose peak wavelength is substantially independent of the wavelength of the respective input signal, and a non-resonant output signal whose peak wavelength is dependent upon the wavelength of respective input signal. A detector is used to detect the two output signals, and by distinguishing the resonant output signals from the non-resonant output signals, data about the analyte content of the sample is determined. Principal components regression analysis or multivariate quantitative analysis can be applied to the output signals, for the purpose of distinguishing between the resonant and non-resonant signals. The method and apparatus can also distinguish resonant output signals from each other, and non-resonant output signals from each other.
Abstract:
Methods for modulating the rates and dose responses of immunoassays through the incorporation of one or more detergents into the immunoassay reaction are disclosed. The methods are particularly suitable for automated immunoassay formats, especially with formats that use analyte-biotin bidentate reagents. The methods may be used to facilitate the detection of any desired, preselected pharmacological agent.
Abstract:
A centrifuge system (10) and method includes generating a radio frequency excitation field within a housing (32) containing a rotor (16) of interest. The excitation field may be generated by an exciter coil (37) fixed to the cover (34) of the housing. The rotor includes a locking knob (23) that encloses a receiver coil (25) inductively coupled to the exciter coil. The excitation field causes current flow through the receiver coil. The current is rectified and used to power encoding circuitry. The encoding circuitry produces a modulated signal unique to the rotor or to a model in which the rotor is classified. The encoded signal is transmitted from within the locking knob to a reader coil (34) connected to the housing of the centrifuge. The reader coil receives the encoded signal, whereafter the signal is decoded and used to identify the rotor or rotor model.
Abstract:
A method and system of determining an operation parameter for a centrifuge includes measuring one or more physical characteristics of a rotor interchangeably supported by a rotor drive. In the preferred embodiment, windage is measured at a first rotational speed and a speed-dependent signal is generated to adjust a vacuum system based upon changes in rotational speed of the rotor. Changes in windage may also be used as a basis for adjusting a refrigeration circuit. Either as an alternative or in addition to monitoring windage, the moment of inertia can be measured and used to adjust adaptive circuitry. For example, the drive circuitry may be adjusted based upon a determination of inertia as the physical characteristic of interest. The method and system isolate inertia and windage as the main forms of resistance to acceleration of the rotor.
Abstract:
Bidentate reagents for rapidly and quantitatively assaying the concentration of pharmacological agents in biological samples are described. The reagents are used in an immunoassay format for determining the concentration of desired, preselected pharmacological agents, such as benzoylecgonine, cocaine, an opiate, PCP, digoxigenin, acetaminophen, carbamazepine, phenytoin, primidone, theophylline, an aminoglycoside antibiotic, vancomycin, quinidine or a cannabinoid.
Abstract:
Methods and reagents for the detection and exponential amplification of target nucleic acid molecules are disclosed. The method generally employs a Primer Oligonucleotide which hybridizes in concert with a Blocker Oligonucleotide on a strand of the target molecule, and an End-Run Oligonucleotide which can hybridize to the Blocker Oligonucleotide.
Abstract:
An automated method and apparatus for performing biopolymer synthesis on a two-dimensional support surface (56) whereby a two-dimensional matrix or array of biopolymers are obtained on the surface. An applicator (10) in the form of a thick plate (12) having in a surface (16) at least one cavity in the form of an open chamber or channel (14) is used for applying reagents to the surface (56) of a solid phase support material. The applicator (10) is positioned over the solid support material (56) with the surface having the cavity (14) sealed against the material surface. For each cavity (14), reagents for synthesis are introduced sequentially into one end of the cavity and collected from the other end of the cavity. A one-dimensional array of biopolymers are thus formed on the support material (56), where each element of the array contains a population of biopolymers having identical sequence. Further synthesis of additional biopolymers is performed by linearly moving or rotating the applicator (10) relative to the support material (56) and carrying out synthesis procedure so that another one-dimensional matrix or array of biopolymers are formed at an offset position to the previous array. At each overlapping region of the two arrays, a cell of biopolymers are formed which each comprises a strand from the first array and a strand from the second array. The result is a two-dimensional array of biopolymers of different sequences at each discrete cell. The arrays of discrete cell containing different biopolymers may be used to conduct hybridization reaction analysis of a biological sample.
Abstract:
Methods for controlling and varying electroosmotic flow in coated capillary electrophoresis columns under electrophoretic conditions are disclosed. The methods described herein involve varying the concentration of a multi-valent buffer compound in electrophoresis buffer compositions in order to control the electroosmotic flow in capillary columns having interior surfaces coated with charged organic coatings. Increasing the concentration of a multi-valent buffer compound which has a charge opposite the charge of the organic coating, in the electrophoresis buffer results in a decrease in electroosmotic flow. Decreasing the concentration of a multi-valent buffer compound results in an increase in electroosmotic flow. The ability to control electroosmotic flow provides enhanced resolution and optimizes separations of electrophoresis sample components.
Abstract:
Coated capillary electrophoresis columns and methods for their use in electrophoretic separations are disclosed. The coated capillary columns include a length of tubing having an interior surface coated with at least one cross-linked organic multivalent ionic compound capable of ionic interaction with charged chemical functionalities on the tubing interior surface. Exemplary columns are prepared by cross-linking a multi-functional amine compound with a diepoxide, alkylating the cross-linked multi-functional amine compound to form a cross-linked quaternary ammonium compound, and then contacting the interior surface of capillary tubing with the cross-linked quaternary ammonium compound.
Abstract:
A method for making a preconjugate comprising an immunogenic species of a polymorphic analyte is disclosed. The method is carried out by reacting an activated binding moiety, and a polymorphic analyte at room temperature for between about 10 hours and about 60 hours. The attaching reaction results in an excess of the preconjugate comprising the immunogenic species of the polymorphic analyte. The preconjugate can be used to make an immunoreactive conjugate useful as a developer antigen in a competitive inhibition immunoassay for the polymorphic analyte.