Abstract: Systems, and components thereof, for analyzing samples. These systems include apparatus and methods for generating, transmitting, detecting, and/or analyzing light, including without limitation high-throughput optical screening devices for analyzing samples at one or more assay sites. These systems also include apparatus and methods for supporting samples for analysis, including without limitation multiwell sample holders such as microplates.

Abstract: Apparatus and methods for optical illumination and/or detection with improved flexibility and/or read speed. The apparatus and methods may include mechanisms for selecting and switching between multiple excitation wavelengths and/or simultaneously reading from a plurality of sample sites. The apparatus and methods may be used with microplates, PCR plates, cell culture plates, biochips, chromatography plates, microscope slides, and other substrates for high-throughput screening, genomics, SNPs analysis, pharmaceutical research and development, life sciences research, and other applications.

Abstract: The invention encompasses an improved method for measuring membrane potential using compounds of the formula I as potentiometric probes. These probes may be used in combination with other fluorescent indicators such as Indo-1, Fura-2, and Fluo-3, such probes may be used in microplate reading devices such as FLIPR™, fluorescent imaging plate reader, sold by Molecular Device Corp., of Sunnyvale, Calif.; flow cytometers; and fluorometers.

Abstract: Apparatus and methods for combining multiple modes and methods of optical detection, postprocessing, and/or feedback loops in bioanalytical measurements. The methods may include (1) positioning a composition at an examination site in a multi-mode instrument; (2) detecting light transmitted form the composition using the multi-mode instrument in a first optical measurement mode; (3) detecting light transmitted from the composition using the multi-mode instrument in a second optical measurement mode, the second mode being different than the first mode; and (4) computing a quantity related to a property of the composition using the light detected in at least one of the optical measurement modes. These steps may be performed on one or more samples, simultaneously and/or sequentially. The quantity may relate to photoluminescence, chemiluminescence, absorption, and/or scattering, among others.

Abstract: A light source with multiple parallel beams is combined with a pair of opposing mirrors mounted on a rotating fixture and with a fixed aperture to produce a single output beam. Through the motion of the rotating fixture, the pair of mirrors shifts the location of the output of each input beam passing through the device so as to sequentially channel each beam into the optical path defined by the aperture. Thus, the input source corresponding to the output beam may be quickly switched by rotating the pair of mirrors to the position that produces the appropriate shift of the beam selected from the light source. In another embodiment of the invention, the pair of opposing mirrors is replaced by a transparent block similarly mounted on a rotating fixture.

Abstract: Systems, including compositions and methods, for measuring pH, particularly in cells, organelles, and other samples. The compositions include pH-sensitive fluorescent and fluorogenic 2′,7′-dialkylfluorescein derivatives and associated nonfluorescent precursor compounds. The compositions may permit ratiometric measurement in the excitation spectrum and the emission spectrum. The methods include adding a precursor compound to a sample cell, incubating the sample cell to release the free indicator, illuminating the sample cell, and detecting the fluorescence response of the free indicator.

Abstract: The present invention relates to a photometric device for measuring optical parameters. The invention functions in the ultraviolet light range through use of a monochromator and splits the test light in multiple channels by a rotor assembly, including a mirror.

Abstract: Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte.

Abstract: A pipette nozzle that achieves a consistently high quality seal between the nozzle and the interior surface of a replaceable pipette tip is provided. In one aspect, the end portion of the nozzle is tapered. The tapered nozzle aids pipette tip engagement in an automated system by relaxing the tolerance on the co-location of the pipette tip and the syringe nozzle. Additionally, the tapered end portion promotes tip sealing. In another aspect of the invention, a small ridge is located on the tapered portion of the nozzle. The ridge forms a seal with the interior surface of the pipette tip. The ridge, in combination with the tapered portions of the nozzle located on either side of the ridge, create three separate interface regions.

Abstract: A high-throughput light detection instrument and method are described. In some embodiments, switch mechanisms and optical relay structures permit different light sources and/or detectors to be selected for different applications. In other embodiments, switch mechanisms and optical paths permit top/bottom illumination and/or top/bottom detection, or combinations thereof.

Abstract: Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte.

Abstract: Xenon arc lamp systems having improved high-voltage power supplies, particularly for use in spectroscopic applications.

Abstract: Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte.

Abstract: A method and apparatus for determining the fluorescence, luminescence, or absorption of a sample is provided. The sample may either be contained within a cuvette or within one or more sample wells within a multi-assay plate. A combination of a broadband source, a monochromator, and a series of optical filters are used to tune the excitation wavelength to a predetermined value within a relatively wide wavelength band. A similar optical configuration is used to tune the detection wavelength. An optical scanning head assembly is used that includes mirrored optics for coupling the excitation source to the sample and the emitted light to the detector. An elliptical focussing mirror is used to magnify and focus the light projected from an optical fiber coupled to the source subassembly onto the sample. A portion of the source light is reflected by a beamsplitter onto a reference detector used to monitor the output of the source.

Abstract: A method and apparatus for determining the fluorescence, luminescence, or absorption of a sample is provided. The sample may either be contained within a cuvette or within one or more sample wells within a multi-assay plate. A combination of a broadband source, a monochromator, and a series of optical filters are used to tune the excitation wavelength to a predetermined value within a relatively wide wavelength band. A similar optical configuration is used to tune the detection wavelength. In one aspect, multiple optical fibers are coupled to the excitation source subassembly, thus allowing the system to be quickly converted from one optical configuration to another. In another aspect, the excitation light and the detected sample emissions pass to and from an optical head assembly via a pair of optical fibers. The optical head assembly is scanned across one axis of the sample multi-assy plate.

Abstract: The present invention encompasses a capture membrane comprising a porous filter membrane having a hapten bound directly or indirectly to the membrane wherein complexes formed by specific binding having an anti-hapten bound to a binding member of the specifically binding complex are removed from a solution by the hapten as the solution passes through the membrane. In the preferred embodiment biotin is the hapten and avidin or streptavidin is the anti-hapten.

Abstract: A method and apparatus for determining the fluorescence, luminescence, or absorption of a sample is provided. The sample may either be contained within a cuvette or within one or more sample wells within a multi-assay plate. A combination of a broadband source, a monochromator, and a series of optical filters are used to tune the excitation wavelength to a predetermined value within a relatively wide wavelength band. A similar optical configuration is used to tune the detection wavelength. In one aspect, multiple optical fibers are coupled to the excitation source subassembly, thus allowing the system to be quickly converted from one optical configuration to another. For example, the source can be used to illuminate either the top or the bottom of a sample well within a multi-assay plate or to illuminate a single cuvette cell. Similarly, multiple optical fibers are coupled to the detector subassembly.

Abstract: A method and apparatus for determining the fluorescence, luminescence, or absorption of a sample is provided. The sample may either be contained within a cuvette or within one or more sample wells within a multi-assay plate. A combination of a broadband source, monochromator, and a series of optical filters are used to tune the excitation wavelength to a predetermined value within a relatively wide wavelength band. A similar configuration is used to tune the detection wavelength. In one aspect, multiple optical filters are coupled to the excitation source subassembly, thus allowing the system to be quickly converted from one optical configuration to another. In another aspect, the excitation light and the detected sample emissions pass to and from an optical head assembly via a pair of optical fibers. In another aspect, an optical scanning head assembly is used that includes mirrored optics for coupling the excitation source to the sample and the emitted light to the detector.

Abstract: Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte.

Abstract: The present invention relates to a photometric device for measuring optical parameters. The invention functions in the ultraviolet light range through use of a monochromator and splits the test light in multiple channels by a rotor assembly, including a mirror.