Abstract: Fluorescence validation material comprising first layer and a second layer that is useful as validation and calibration standards as well as validation plates including one or more fluorescence validation materials. Moreover, this invention includes methods for using validation plates and fluorescence validation materials of this invention to validate and calibrate instruments.

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: 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: In a centrifuge having a central stator with a peripheral rotor, an improved suspension for the rotor is disclosed. The central stator is provided with a bore coaxial to the axis of rotation of the rotor. The rotor of the centrifuge motor has a quill shaft support member extending into and rotating within the coaxial bore of the stator. A quill shaft attaches at the bottom of the quill shaft support member and extends upward above the rotor of the centrifuge motor to support a fastening hub for the centrifuge rotor. The rotor of the centrifuge is detached from the rotor of the centrifuge motor so as to define a spatial interval between the supported spinning rotor and the rotor of the motor driving the centrifuge. The centrifuge rotor attaches at the hub and depends downward from the hub with the spatial interval being defined between the rotor of the motor and the rotor of the centrifuge.

Abstract: In a damper for a centrifuge for damping the rotor of the centrifuge when the rotor changes rotational velocity through a critical vibrational rotation speed, an improved vibration damper is disclosed. The damper is of the type wherein a conically shaped shaft extension is thrust into engagement with a friction bushing at a circular and central opening to increase shaft section and shift the critical vibrational rotation speed away from the particular critical vibrational rotation speed being traversed. The conical bushing is engaged by a solenoid and translates side-to-side rotor motion to an energy dissipating up and down motion at the solenoid. The improvement disclosed is a conically shaped cone having a negative radius of curvature in section. For small shaft side-to-side excursion (due to small vibration) this conically shaped cone has an initial small slope with respect to the bushing to provide reduced damping of the rotor when small vibration and hence small displacements effect the rotor.

Abstract: A process and apparatus for predicting the time and position dependent concentration of macromolecules of differing species in a gradient forming solution during centrifugation is disclosed. A mathematical model of the time dependent behavior of gradient forming solutes in a centrifugal field, based upon the underlying physical principles governing sedimentation and diffusion is formulated. The simplifying approximation is made that the wall effects may be ignored, and that the transport of solute may be treated as a one dimensional process with forces dependent only upon the radial distance. A sedimentation diffusion (Lamm) equation in one dimension is numerically integrated. The sedimentation diffusion equation (Lamm equation) for each macrosolute is solved concurrently with that for the gradient forming solute, utilizing the experimentally based density dependent sedimentation coefficient. The equations are solved for incremental time periods for the centrifuged samples in successive radial segments.

Abstract: In an optical system for measuring sample absorption of light at a primary wavelength output from a monochromator, a method of subtracting the effect of secondary wavelength components of light from the monochromator. The sample absorption of light at the primary wavelength including the effect of the secondary wavelength components and at the secondary wavelength are determined. The results are used to obtain the sample absorption of light at the primary wavelength without the effect of the secondary wavelength components.

Abstract: A centrifuge sample is optically scanned during centrifuging. The sample, placed in a centrifuge rotor having a cell with top and bottom windows, is spun until stratification and discrete layering occurs within the sample. Such layering occurs on layers that are precisely normal to the radius of the centrifuge at the point of sample and parallel to the spin axis of the centrifuge. A slit scanner having a slit normal to the sample plane transverses the width of the sample below the cell to detect with precision the precise location of the strata in the cell. A light source is reflected by a toroidal mirror having two radius of curvature. One radius of curvature is selected to collimate rays of light parallel to the layer of the sample. The mirror is ruled with respect to the other radius of curvature to chromatically classify light to preselect band width. Rotation of the mirror preserved collimation but enables selected scanning light frequency.

Abstract: A thermoelectric cooling design of the type having a nonconducting substrate mounting thermoelectric coolers is improved. Provisions for a flexible can and improved heat dissipation from the thermoelectric coolers are provided. For improved thermal response, the refrigerated vacuum can is provided with thin walls of high purity aluminum with the result that deformation of the wall surface, especially the bottom wall surface can occur both with respect to installation. A plurality of can heat sinks are placed on the walls of the can to form a unitary and locally rigid side wall to the can at the point of attachment. At least one thermoelectric cooler is communicated to the can heat sinks at a first side for receiving heat energy from the can. A second discharge heat sink is communicated to each thermoelectric cooler for dissipating heat energy from both the can and the thermoelectric cooler.

Abstract: To enable centrifuging to occur at precisely determined sample temperatures, a method of centrifuge calibration which permits rapid and accurate refrigeration of the rotor containing the sample is disclosed. A rotor with sample to be centrifuged is placed within a centrifuge can. Temperature of the radiometer T.sub.ra, and temperature of the surrounding refrigerating can T.sub.c is determined at a first time, t.sub.0. Thereafter, and at a second time t.sub.1, temperature of the radiometer T.sub.ra, and the temperature of the surrounding refrigerating can T.sub.c are equilibrated. The temperature excursion between t.sub.0 and t.sub.1 for the temperatures of the radiometer T.sub.ra and the temperature of the refrigerating can T.sub.c are measured to yield respective .DELTA. T.sub.ra and .DELTA. T.sub.c. The radio of .DELTA. T.sub.ra /.DELTA. T.sub.c is taken to give a constant which comprises the view factor from the radiometer for the particular shape of rotor and the surrounding can.

Abstract: A centrifuge sample is optically scanned during centrifuging. The sample, placed in a centrifuge rotor having a cell with top and bottom windows, is spun until stratification and discrete layering occurs within the sample. Such layering occurs on layers that are precisely normal to the radius of the centrifuge at the point of sample and parallel to the spin axis of the centrifuge. A slit scanner having a slit normal to the sample plane transverse the width of the sample below the cell to detect with precision the precise location of the strata in the cell. A light source is reflected by a toroidal mirror having two radius of curvature. One radius of curvature is selected to collimate rays of light parallel to the layer of the sample. The mirror is ruled with respect to the other radius of curvature to chromatically classify light to preselect band width. Rotation of the mirror preserved collimation but enables selected scanning light frequency.

Abstract: An apparatus and method of protecting a centrifuge from rotor overspeed and resultant mishap by computation of the rotor moment of inertia is disclosed. In the preferred embodiment, a centrifuge is driven by a rotor mounted on a shaft which shaft is in turn driven by a constant current motor. A tachometer for detecting angular velocity of the drive shaft is used. A desired and ultimate centrifuge operating speed is selected by the operator. The times at which the rotor passes through discrete speeds are recorded and from the time difference the moment of inertia is computed. The moment of inertia can thereafter be utilized to discretely identify or "finger print" rotors to disqualify certain rotors from use in particular centrifuge protocols and establish gross limits of centrifuge operating speed.

Abstract: A thermoelectric cooling design of the type having a nonconducting substrate mounting thermoelectric coolers is improved. Provisions for a flexible can and improved heat dissipation from the thermoelectric coolers are provided. For improved thermal response, the refrigerated vacuum can is provided with thin walls of high purity aluminum with the result that deformation of the wall surface, especially the bottom wall surface can occur both with respect to installation. A plurality of can heat sinks are placed on the walls of the can to form a unitary and locally rigid side wall to the can at the point of attachment. At least one thermoelectric cooler is communicated to the can heat sinks at a first side for receiving heat energy from the can. A second discharge heat sink is communicated to each thermoelectric cooler for dissipating heat energy from both the can and the thermoelectric cooler.

Abstract: In a double thermal coupled radiometer for preferable use with a centrifuge, an improved radiometer configuration is disclosed. The isothermal radiometic system improved is of the double junction variety (preferably copper-constantan-copper) and includes a black body housing defining a central concavity. The central concavity has a black body disk at the bottom thereof. The disk is preferably suspended by a copper and a constantan wire with one junction formed on the surface of the disk and the other junction formed on the surface of the housing. The improvement includes a plurality of and preferably three annular baffles defining central, circular and preferably concentric opening. These baffles are lodged in the opening of the housing above the mounted radiometer disk. The annular baffles on the side towards the radiation sources are coated as a black body so as to increase the thermal coupling of the black body housing to the ambient being radiometically observed.