Abstract: An X-ray inspection system in which a thin X-ray absorber is placed upstream of an object under investigation so as to remove low energy X-rays, typically below 0.5 MeV. The absorber may be a sheet of lead 10 mm thick. Where the X-ray inspection system which incorporates a detector which relies on the electro-magnetic cascade effect produced in suitable materials when bombarded with X-rays so that energy is transferred into the material at different depths depending on the energy of incident X-rays, and the first component on which the X-rays impinge comprises a relatively thin crystal this unwanted background may be reduced by placing a vessel containing a fluid whose density is less than that of air, in front of the detector crystal array. Typically the fluid is helium at atmospheric or slightly greater than atmospheric pressure. The background can be reduced by applying a magnetic field in the region in front of the detector crystal array so as to sweep away electrons from that region.

Abstract: A method and apparatus for the measurement of radiation, especially fluorescence from samples in assays, wherein a plurality of micro-sample light emitting sites are imaged simultaneously onto a detector array by a plurality of miniature objectives, one for each sample site and focussed thereon, producing parallel beams of light arranged in parallel and spaced apart, which beams are focussed at a pinhole aperture and then reconstituted as parallel beams for incidence on the detector array.

Abstract: A fiber optic epi-fluorescence imaging system in which the optical fibers are rearranged so that the system can be used for measuring luminescence samples. The system comprises at least two optical fibers (32, 46) or bundles of fibers which lead to a CCD camera (74), the fibers or bundles of fibers from all samples being arranged in two sets, a first set which are formed from a non-fluorescing material and a second set which are formed from a material which may fluoresce but enables the fibers formed therefrom to have a higher numerical aperature than those of the first set.

Abstract: A system for imaging radiation emitted by assay couples into a photoelectric detector, the system including a fibre optic bundle (100) for conveying light to the detector, wherein a microlens (118), preferably a drum lens, is located at the impact end of the fibre optic bundle to match the field of view of the bundle to a potential area of interest in a sample.

Abstract: A fiber optic epi-fluorescence imaging system in which the optical fibers are rearranged so that the system can be used for measuring luminescence samples. The system comprises at least two optical fibers (32, 46) or bundles of fibers which lead to a CCD camera (74), the fibers or bundles of fibers from all samples being arranged in two sets, a first set which are formed from a non-fluorescing material and a second set which are formed from a material which may fluoresce but enables the fibers formed therefrom to have a higher numerical aperture than those of the first set.

Abstract: Apparatus for detecting light emitted by an assay sample is provided, in which light emitted by the sample is collected for transmission to a photosensitive detector such as a charge coupled device (CCD) (74) by an optical fiber 78 bundle. The cross-sectional area of the optical fiber bundle corresponds to the area of the sample, the end of which is located close to the sample for detecting any light emitted therefrom. Selected fibers (30) of those making up the bundle may be separated from the remainder and extend to a source of excitation radiation (76) to convey excitation radiation to the sample. The remaining fibers (32, 38) serve to collect emitted light and provide a light path to the photosensitive detector (74). A blocking filter and an interference filter are placed between the fiber bundle and the detector. The blocking filter may be between the bundle and the interference filter or between the latter and the detector.

Abstract: An optical system for imaging a multiwell sample plate onto a CCD camera, wherein light from the illuminated sample plate (26) is imaged by one or more lenses (20,24) onto a fibre optic taper (22), bonded to the input face of the camera (28).

Abstract: A fiber optic coupling plate (24) has a sample viewing face for receiving light from a sample (12), an output window (18) for conveying sample originating (emitted) light to an imaging detector and an additional window through which excitation radiation can be projected. A primary light is provided through the plate made up of optical fibers which will convey light entering the viewing face, directly and with minimal loss, to the output window, and a secondary light path separate from the primary light path, by which excitation radiation entering the additional window is conveyed to the viewing face for irradiating the sample.

Abstract: Method of performing a biomedical assay comprising the steps of exciting the sample or samples with incident radiation of a given wavelength, thereby causing the sample to emit radiation of a different wavelength, measuring the quantity of light falling on a detector receiving the emitted radiation from the sample, thereby to produce a first measurement, illuminating the sample or samples with incident radiation in a manner which does not cause the sample to emit any significant radiation, again detecting the quantity of light falling on the detector, thereby to produce a second measurement and correcting the first measurement, with respect to the second measurement.

Abstract: The present invention provides a detection system comprising means (12) for supporting a multiple sample assay (11) in an inspection station, plural addressable photosensitive detector elements in an array (20) which is positioned relative to the inspection station, means (30, 32) for addressing the groups of elements at regularly occurring intervals of time so as to generate linked numerical values for analysis, means (44, 46) for computing the arithmetic mean of the linked numerical values read out, and means for supplying as output information the numerical value of the computed arithmetic mean of the linked values. A method of analyzing a multiple sample assay is also provided.

Abstract: An imaging system for fluorescence assays includes a fiber optic coupling plate (20, 24, 26) for transmitting radiation emitted by a sample (18) towards a camera. This is combined with an interference filter (22) so as to enable highly sensitive transmission of radiation to the camera, according to wavelength. The interference filter may be combined with a fiber optic coupling plate in which sample sites or wells of an array are viewed by separate fiber optic bundles, each bundle transmitting emitted light from a one sample or well to a discrete region of the field of view of the camera.

Abstract: A fiber optic coupling plate (24) has a sample viewing face for receiving light from a sample (12), an output window (18) for conveying sample originating (emitted) light to an imaging detector and an additional window through which excitation radiation can be projected. A primary light is provided through the plate made up of optical fibers which will convey light entering the viewing face, directly and with minimal loss, to the output window, and a secondary light path separate from the primary light path, by which excitation radiation entering the additional window is conveyed to the viewing face for irradiating the sample.

Abstract: A fibre optic coupling plate (24) has a sample viewing face for receiving light from a sample (12), an output window (18) for conveying sample originating (emitted) light to an imaging detector and an additional window through which excitation radiation can be projected. A primary light is provided through the plate made up of optical fibres which will convey light entering the viewing face, directly and with minimal loss, to the output window, and a secondary light path separate from the primary light path, by which excitation radiation entering the additional window is conveyed to the viewing face for irradiating the sample.

Abstract: A method of detecting the presence and position of labelled material in a sample in which the labelled material either gives off light or can be stimulated to do so. The sample is imaged onto a CCD array which is scanned following each exposure. A cooled CCD camera or an image intensified CCD camera may be used. Measurements are performed on the data signals so obtained, to identify clusters of data values from adjacent regions of the CCD array caused by light incident on those regions. The measured signal values are compared with at least one threshold so as to distinguish clusters resulting from light emitting regions of labelled material from the remainder of the sample and the centroid of each light produced cluster of data values is computed with reference to the camera array, and a signal value corresponding to the centroid coordinates is stored in a memory together with the centroid coordinates of any other light produced clusters identified during the same interrogation.

Abstract: A method of detecting the presence and position of radio isotope material in a sample is described comprising the steps of: exposing the sample to a phosphor, repetitively imaging the phosphor onto an image intensified CCD camera, scanning the camera CCD array and interrogating the charge pattern thereon following each exposure, performing measurements on the data signals obtained thereby to identify clusters of data values from adjacent regions of the array caused by light emitted by the image intensifier onto those regions and comparing the measurements with threshold values and parameter values so as to distinguish clusters resulting from light emitted as a result of radioactive decay events energizing the phosphor, from other light producing events, computing the centroid of each cluster of data values identified as a radioactive decay event with reference to the camera array and storing the centroid coordinates in a memory together with the centroid coordinates of any other radioactive decay produced clu