Abstract:
A normalization system for multi-photodetector single photon counting luminescent measuring systems and a standard for use in the same. The method comprises calculating one or more counting ratios for each photodetector in the single photon counting system and multiplying counts of unknown samples by the inverse of the appropriate counting ratio. A counting ratio for a particular photodetector is calculated by dividing the count of a standard measured by the photodetector by the count of the same standard measured by a reference photodetector. The particular standard developed employs calcium tungstate: lead as a scintillator and radio-active elements as tritium or carbon-14 thymidine as a means of exciting the scintillator. This standard has the advantages of providing a good model of typical luminescence chemistry and producing an emission pattern which is susceptible to single photon counting.
Abstract:
A new support body (10) for use in a scintillation proximity radioimmunoassay consisting of a scintillation material. The support body (10) of the present invention permits extremely sensitive and specific assays for a broad range of biological and non-biological substances. The support body (10) of the present invention having a ligand (16) coupled to its surface which is capable of selectively biochemically binding to a reactant of interest (11) resulting in a complex (18).
Abstract:
A vial (10) for holding a radioactive sample for radiometric analysis which has an outer surface (14) on which a coating comprising a transparent antistatic agent (18) is deposited to prevent the accumulation of electrostatic charges on the vial. The vial (10) is treated to make the vial free of electrostatic charges by immersing the vial (10) and cap (12) with a solution containing the antistatic agent, spraying the vial (10) and cap (12) with a solution containing the antistatic agent or by contacting the vial (10) and cap (12) in a heated air stream with a flexible substrate carrying the antistatic agent.
Abstract:
A microplate (10) for radiometric analysis having a plurality of sample wells (12) for holding radioactive samples is manufactured from a gas barrier resin which is chemically resistant to hydrocarbon solvents. The resin is typically a rubber modified copolymer which includes at least 50 weight percent of an unsaturated nitrile component and a monomer component which is capable of being copolymerized with the nitrile component. A preferred gas barrier resin is an acrylonitrile-methyl acrylate copolymer. A white pigment, preferably titanium dioxide, is added to the resin to produce an opaque, highly reflective microplate (10).
Abstract:
A scintillation measurement system for measuring optical events produced by scintillators (19) in response to the radioactive decay of a constituent or constituents of a sample (10) to be measured comprises a sample support for positioning a sample in a sample well (11); a bismuth germanate (BGO) scintillation crystal (19), such as Bi4Ge3O12, located adjacent the sample well; a plurality of photodetectors (16, 18) located outside the bismuth germanate crystal (19) for detecting optical events occuring in the sample well (11) or in the bismuth germanate crystal (19) and converting those optical events into electrical pulses; and a pulse analyzing system (40) for receiving the electrical pulses from the photodetectors and determining whether such pulses represent alpha, beta or gamma events. This system can be used with samples containing alpha, beta or gamma emitters, or any combination thereof.
Abstract:
The present invention provides a process of quantifying the number of viable cells in an aqueous suspension of cells using an energy-emitting non-hazardous probe and a probe-trigger. The process provides quantification data in short periods of time without the use of hazardous materials. A process of the present invention can also be used to quantify negatively charged particle number, assay for cytotoxicity, assay for cell proliferation and assay for cell differentiation. Still further, the present invention provides an assay kit for quantification of cells or negatively charged particles.
Abstract:
A method of detecting the presence and position of labelled material in a sample in which the labelled material either gives of light or can be stimulated to do so. The sample is imaged onto an image intensified CCD camera which is scanned following each exposure. 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 emitted by the image intensifier 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. The coordinates from each of a succession of interrogations of the same sample may be stored in an accumulation store to enable a list of the recorded light emissions and/or display of the events, to be produced by reading out the store. Apparatus for performing this method is also described.
Abstract:
A system for aspirating and ejecting microvolume drops (26) of liquid onto porous sites of a substrate wafer includes a microdispenser (16) employing a piezoelectric transducer (60) attached to a glass capillary (62), a means for priming and aspirating transfer liquid (24) into the microdispenser (16), for controlling the pressure of the system liquid (20), and for washing the microdispenser (16) between liquid transfers, and a pressure sensor (14) to measure the system liquid pressure and produce a corresponding electrical signal. The drops are generally in the 10 to 100 micron range and the pores are generally 10 to 10,000 times smaller than the diameter of the drops deposited thereon. The resulting spots are uniform, and only slightly larger in diameter of the drops. The drops are ejected from a distance greater than the diameter of the drops, thus avoiding any contact with the dispenser that could damage the wafer. The system detects dispensing of a drop onto the reaction site.
Abstract:
A fibre optic epi-fluorescence imaging system in which the optical fibres are rearranged so that the system can be used for measuring luminescence samples. The system comprises at least two optical fibres (32, 46) or bundles of fibres which lead to a CCD camera (74), the fibres or bundles of fibres 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 fibres 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 photoeletric detector, the system including a fibre optic bundle (100) for conveying light to the detector, wherein a microlens (118), preferably a drum leans, 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.