Abstract: Biological assay systems often involve suspending magnetically attractable particles in a liquid, and later bringing down the particles from suspension and separating the formed pellet from the supernatant liquid. The invention provides magnetic systems for this purpose, shaped to form an annular or part-annular pellet close to the bottom of the vessel. The systems are suitable for automation.

Abstract: A sampling device includes a cylindrical tube having a smaller diameter portion in which a plunger is mounted for sliding sealing movement. The inner end of the cylinder is sealed from the interior of the tube by a rupturable element, and the plunger has sharp end edge which will rupture the sealing element when the plunger is depressed. The outer end of the plunger is formed with a series of grooves capable of retaining a sample. Depression of the plunger breaks the sealing element and carries the sample into the tube to test its reaction with a reagent previously sealed in the tube. The end of the plunger remote from the sealing element forms a seal in the cylinder. A generally similar arrangement at the opposite end of the tube allows a second reagent to be added to the reagent in the tube.

Abstract: Novel compounds obtainable by reacting together an imido-reagent such as diphenylphosphonimidotriphenylphosphorane) with a chelate of a transition or lanthanide or actinide metal, such as tris(dibenzoylmethide) europium III, has the property of fluorescing in UV radiation. The invention includes solid polymer bodies containing such compounds, or chelates of transition or lanthanide or actinide metals generally, the bodies having the property of emitting light by virtue of internally generated, e.g. by tritium ionising radiation. The body is preferably of polystyrene formed by polymerising the monomer in the presence of the compound or metal chelate.

Abstract: Agents for the diagnosis or treatment of hypoxic cells comprise a bioreductive moiety such as 2-nitroimidazole, and a metal chelating moiety which is a bis-amine oxime of which a carbon atom adjacent a nitrogen atom is linked to the bioreductive moiety. A chelated metal atom or ion preferably Technetium-99m. The agent diffuses into cells where the 2-nitroimidazole is reduced thus trapping the chelated metal in the cell.

Abstract: Tridentate mono-anionic ligands have the structureX-A-Y-Q-Zwhere each of X and Y is independently P, As or N,Z is phenol, thiophenol or thiol, andA and Q are hydrocarbon linking groups.The ligands from cationic complexes with Technetium-99m, e.g. [Tc.sup.III K.sub.2 ].sup.+ where K is the ligand, having useful imaging properties.

Abstract: Method of performing enzyme assays using the technique of surface plasmon resonance spectrometry (SPRS). An SPRS surface carries an immobilized reagent which is capable of being released by an enzyme. A fluid sample containing the enzyme is brought into contact with the solid surface, and release of the reagent monitored by SPRS.

Abstract: A one-step assay for the free portion of a ligand in a biological sample involves incubating a mixture of the sample with a labelled antibody for the ligand and a ligand analogue which competes with the ligand for binding to the antibody. The assay is characterized by choosing a ligand analogue which has a lower affinity for the antibody than does the ligand. An insolubilised ligand analogue preferably has a binding affinity for the antibody from 0.01% to 10% of that of the ligand. Ligand/ligand analogue pairs exemplified are T4/T3 (Thyroxine/Tri- iodothyronine); Testosterone/etiocholanol; and T3/T2.

Abstract: Complexes useful as radiopharmaceuticals contain the .sup.99m Tc-NO moiety and up to four organic ligands which confer biological target-seeking properties on the complex. Preferred are mono-cationic complexes, particularly having the formula[.sup.99m Tc(NO)L.sub.2 X].sup.+where X is halide or pseudohalide and L is a bidentate ligand for Technetium, which have interesting properties for use as heart visualizing agents. Examples of ligands include di-(dialkyl and diphenyl)phosphinoethanes and o-phenylenebisdimethylarsine. The complexes may be made by reacting generator eluate pertechnetate with a hydroxylamine salt and with the ligands, preferably in a single step by providing a reaction mixture containing the three reagents optionally in the presence of a reducing agent.

Abstract: A surface plasmon resonance (SPR) detector includes a laser source for generating radiation which is reflected off a concave reflector to a point or line of incidence on the interface between a glass slide and a metal layer. A single pencil beam from the laser is scanned by a moving mirror across a small arc, covering those angles of incidence within which surface plasmon resonance occurs. A sensitive, for example antibody, layer overlies the metal layer to form a combined layer, and a sample to be tested is passed across the antibody layer. Any binding which occurs with the antibody layer results in the refractive index of the layer changing, and this change may be detected by monitoring the strength of the beam internally reflected at the point or line. A light detector enables the beam to be measured.

Abstract: The present invention is drawn to a surface plasmon resonance (SPR) sensor in which the phenomenon of long-range surface plasmon resonance is used to develop a highly sensitive detector for use in biological, biochemical or general chemical testing. The sensor includes a laminar structure having of a high refractive index glass block, a membrane of dielectric material, a thin metal layer, and a sensitive layer. A sample to be tested is brought into contact with the sensitive layer. The refractive index of the dielectric layer and that of the layer (sensitive layer/sample) on the opposite side of the metallic layer should be equal, or nearly so, and the refractive index of the glass block should be higher than this so that total internal reflection takes place at the interface between the block and the membrane. Light from a laser source is totally internally reflected at this interface, and the strength of the reflected beam is monitored by a light detector.

Abstract: Apparatus for the high resolution imaging of macromolecules and interactions involving macromolecules. The apparatus comprises a surface (10) on which the macromolecule under test is placed and a plurality of fine probes (13). Means (not shown) are provided for scanning each of the probes (13) across a small area of the surface 10 in such a way that the total output from the probes covers the whole surface. Means (not shown) such as a scanning tunnelling and/or atomic force detector are used to monitor the movement of the individual probes in a direction transverse to the surface (10) and display means (not shown) are used to display the transverse movement of the probes, being illustrative of the topography of the surface.

Abstract: A biological sensor which utilizes the phenomenon of surface plasmon resonance to detect the refractive index change which occurs when two components--for example antibody and corresponding antigen--react with one another. Surface plasmon resonance takes place at the sloping exit surface of an optical waveguide such as a fiber optic 23. The input end of fiber optic 12 is connected to a light source 12. A layer 25 of metal is applied to the sloping exit surface so as to cause total internal reflection of the light proceeding down the fiber optic. Reflected light is detected by a detector 13. A sensitive, for example antibody, layer 26 is applied to the metal layer. Sample (not shown) reacts with layer 26 in such a way that the refractive index changes. Provided conditions are correct, this variation in refractive index can be monitored in detector 13 by virtue of the surface plasmon resonance which occurs in the area of total internal reflection.

Abstract: This invention concerns novel bidentate ligands L having two phosphorus or arsenic atoms. Cationic complexes of the ligands with Technetium-99m, e.g. having the formula [TcO.sub.2 L.sub.2 ].sup.+, are useful for body imaging, particularly myocardial imaging. The ligands have the general formulaY.sub.2 QZQY.sub.2where Q is phosphorus orZ is a --CC-- or --CCC-- or --COC-- groups,the four groups Y are all C1-C8 saturated hydrocarbon or fluorohydrocarbon with 1-3 ether oxygen atoms.

Abstract: A surface plasmon resonance (SPR) sensor is adapted for biochemical and similar testing on large area samples such as the gel of an electrophoresis apparatus. The gel is sandwiched between a pair of plates. One of the plates is of transparent material and, sandwiched between itself and the gel is a metal layer of a mosaic of silver dots. Light from a source is directed via a reflector and undergoes total internal reflection at the interfacce between the transparent plate and metal layer. The reflected light is passed via another reflector to a light detector. The equipment is arranged so that SPR occurs at the metal layer, which resonance is critically dependent upon the refractive index of the gel. The structure including the light source and detector, together with reflectors is caused to scan across the gel surface to enable a two-dimensional representation of the changes in refractive index across the gel to be built up. This enables the progress of sequencing to be monitored.

Abstract: A surface plasmon resonance (SPR) sensor in which a membrane is used to enable the sensitive material to be readily changed to enable tests to be carried out on a sequential basis simply by moving or changing the membrane. In one embodiment, the membrane takes the form of a continuous film (24) which lies against and is moveable across by means not shown, a transparent plate (17) which forms part of the SPR sensor. The film (24) comprises a layer (31) of flexible transparent material to which is applied a thin layer (32) of metal such as silver. Applied to layer (32) is a layer (33) of sensitive material. The final layer (34) is a preformed layer of hydrophyllic plastics material which incorporates troughs (37) and passageways (35,38) for the transfer of sample across the sensitive layer. Light from a laser (not shown) is subject to total internal reflection at the interface between the transparent layer (31) and metal layer (32), and the reflected light is collected by a light detector (not shown).

Abstract: In a proton/neutron source incorporating a cyclotron, in particular a superconducting cyclotron having a cylindrical superconducting magnet incorporating superconducting magnetic coils associated with pole pieces, a stream of ionized particles, such as H.sup.- particles, is continuously injected into the center of the cyclotron beam space and is accelerated outwards in a spiral path under the combined effect of the magnetic field from the superconducting magnet, and RF energization applied to sector-shaped electrodes. When the particles reach the required energy, they are removed from the spiral path by septa electrodes, and are passed across a proton storage ring in a path of rapidly increasing radius under the influence of the falling magnetic field of the superconducting magnets.

Abstract: A sensor uses the principle of surface plasmon resonance (SPR) to monitor the progress of the reaction between a sample and a sensitive layer (for example an antibody layer). The layer is applied to the rear surface of a metallic film formed on the surface of an optically transmissive component in the form of a hemicylindrical lens and slide. Collimated light from a source is applied via a lens which focuses the incoming beam to a focus at a point to form a fan-shaped spread of light incident at the point. The light is internally reflected at the point, and emerges from the component to be applied to a dectector array which latter is electronically scanned. The angle of incidence of the light at the point is such as to span that angle which gives rise to surface plasmon resonance, together with a range of angles thereabout so that the progress of the resonant condition, as the reaction between the sample and the sensitive layer proceeds, can be monitored.

Abstract: A cyclotron having a cylindrical superconducting magnet which generates an axial magnetic field and has a central opening or chamber of substantially circular cross-section. The accelerating beam space is located in this chamber lying normal to the axis of the magnetic field. The azimuth variation of magnetic field as well as the isochronous radial variation of magnetic field required to control the orbiting of the ion beam in the beam space, are provided by ferro-magnetic pole pieces located in the axial chamber, which interact with the magnetic field to cause the required field variations. Interposed between the pole pieces are resonant frequency members which provide the radio frequency energization to accelerate the ion beam around the beam space. Having the whole of the central chamber free for top and bottom access enables the pole pieces to be given an efficient design shape.

Abstract: The invention concerns cationic complexes of Technetium-99m with bidentate ligands (L), including complexes having the formulae [Tc(NO) X L.sub.2 ].sup.+ and [Tc L.sub.3 ].sup.+, which are of interest as heart imaging agents. The ligands are characterized by having the formula Y.sub.2 QZQY.sub.2, where each Q is phosphorus or arsenic, Z is a 2 or 3 carbon atom linking group, and at least one of the groups Y and Z includes at least one --COC--ether group.

Abstract: A method and apparatus for use in biological testing. The apparatus comprises electrophoresis apparatus comprising a tank (1) the interior of which is formed with a raised portion (5) which splits the tank into the two compartments (6,7) containing electrophoresis electrolyte. Electrodes (8) are provided in each compartment. Electrophoresis is carried out through a gel (not shown) supported by a rigid porous plate (11). The gel is cast onto the porous plate with a transfer membrane (not shown) between the porous plate and the gel. Further electrodes (20,21) are mounted below and above the gel respectively. The method of the invention comprises a first stage using the electric field produced by the electrodes (8) to draw the samples through the gel and a second stage using the electric field produced by the electrodes (20,21) to draw the distributed macromolecules onto the transfer membrane.