Abstract: A system and method for manipulating magnetic particles in a solution to separate nucleic acid molecules from cell components in a cell solution. The system and method employ a device capable of receiving a plurality of tubes, each of which contain respective sample and paramagnetic particles. The device includes heating and cooling devices to facilitate a lysing step to release the nucleic acid molecules from the cells in the cell solution. The device further includes moveable magnets which can be moved proximate to and away from the tube to hold the paramagnetic particles to which the nucleic acid molecules become bound, so that the molecule-bound particles can be separated from the remainder of the solution, and washed as appropriate. The system also employs an electromagnet which is capable of demagnetizing the particles to allow the particles to freely mix with solution, such as elution solutions which are used to unbind the molecules from the particles.

Abstract: An improved method for separating materials is provided, using colloidal, magnetizable aggregates, optionally silanized, and coated with a one or more layers of novel polysaccharide derivatives. Materials separated by the aggregates of the invention include inorganic and organic molecules, viruses, organelles, and cells. The invention also relates to a kit for separating such materials. The separated materials are useful in analytical and preparative or in diagnostic and therapeutic techniques.

Abstract: Spheres are released from within plurospheres by mixing a fluid with fly ash or bottom ash particulate material obtained by burning coal to form a slurry. The slurry is vibrated at an ultrasonic frequency and with sufficient power that plurospheres in the particulate material are cracked open to release spheres of the material which are encapsulated within the plurospheres. The so-treated material is separated from the slurry to obtain the released spheres.

Abstract: A method and apparatus for magnetically separating magnetizable particles from a mixture of magnetizable and nonmagnetizable particles of similar size and density by passing the particles through a magnetic field generated by a cylindrical coil around the outside of the column of the separator, and enhanced by a ferrous metal mass or ring within the column located generally centrally of the coil.

Abstract: A conveyor system for conveying items, such as bottles and cans, from a first position whereat they are magnetically encoded by using magnetic energy and wherein the coded item is detected at a spaced apart second position using a magnetic sensing device such as a Hall effect sensor. The magnetic encoder can place different levels of magnetism on the container caps and the Hall effect device can detect these different levels of magnetism. By using this technique, containers may be divided into different categories by placing different levels of magnetism on them. The Hall effect device can differentiate these different levels of magnetism which allows the system to do selective sorting at the downstream station.

Abstract: Processes for purification of saline minerals using magnetic separation are disclosed. In particular, saline minerals can include trona, borates, potash, sulfates, nitrates and chlorides. The magnetic separation can include high intensity magnetic separation which can be conducted at greater than about 20,000 Gauss and up to greater than about 50,000 Gauss. Other embodiments of the invention include calcination of a saline mineral in an inert atmosphere or in an oxygen-containing atmosphere at a high temperature prior to magnetic separation. A further embodiment of the invention includes pre-alignment of particles on a surface to align the particles of high magnetic force during a magnetic separation step. Also disclosed are various embodiments of magnetic separation which include subjecting an ore to a preliminary magnetic field prior to magnetic separation.

Abstract: A ferrographic apparatus and method incorporate a priming operation that moves a priming fluid, in a direction opposite to the flow direction subsequently followed by the sample fluid, through a fluid pathway including the flow chamber. The fluid pathway is configured to facilitate dissipation of any gas bubble introduced into it during the priming operation and to reduce adventitious deposition of specimen material at locations other than the substrate. Sample fluid to be analyzed is added to the reservoir so as to form a bubble-free interface with the priming fluid, and the direction of movement through the flow chamber is reversed. The resulting continuous fluid column is advanced through the fluid pathway so that the sample fluid enters the flow chamber through the inlet port and passes through the magnetic field gradient, exiting through an orifice at the opposite end of the flow chamber serving as the outlet port.

Abstract: A top feed, wet drum magnetic separator capable of treating, removing tramp metal from the full flow discharge of a grinding mill having a feed box which provides overflow capacity, velocity break to minimize turbulence, and spread the slurry evenly across the drum surface. A flow transition is provided to the rotating drum surface. A fixed magnet assembly is supported inside the drum. Barrier walls contain the flow and a cover confines the flow over the drum. A partitioned product hopper collects metallic fragments separately from the bulk slurry flow. A spray bar is provided to clean the drum.

Abstract: Method and apparatus for enabling resuspension wash and magnetic localization of sample components bound to particles with magnetic properties in reaction vessels during separation and wash for enhanced chemiluminescent signal generation in biomedical assays. The assays involve moving reaction vessels past magnets that partially localize the particles prior to passing a reduced strength magnet where washing occurs, with or without resuspension, after separating out the unbound particles and liquid. The band of particles is subsequently resuspended in acid for chemiluminescent purposes. A variety of magnet configurations are employed to realize the reduced strength magnet. Reduced strength magnets adjacent the full width magnets prevent the band of magnetic particles from becoming split. The localized particles enable more efficient resuspension by reagent.

Abstract: A placer gold separating method includes subjecting placer gold-and gold ore-containing sand and gravel layers accumulated on the bottom of the water of a river and placer gold- and gold ore-containing sand and gravel layers formed deep in the ground to excavation or suction excavation by utilizing a water pressure difference. This causes a mixture of the excavated or suction excavation placer gold- and gold ore-containing sand, gravel and water to flow horizontally by the action of a pressure fluid. The placer gold and gold ores are separated by utilizing a specific gravity difference while the mixture is flowing. A placer gold mining boat used to practice this method is provided thereon with a combination of a suction excavation component, a mixture transfer component, a component for separating placer gold by utilizing a specific gravity difference, and a component for discarding the remaining mixture from which the placer gold has been separated.

Abstract: A trash container lid facilitates easy disposal of food scraps while inhibiting inadvertent disposal of tableware. The trash container lid includes a cover configured to cover at least a portion of an opening in a trash container. A chute is formed in the cover and is configured to receive food scraps and to direct the food scraps into the trash container. At least one magnet is disposed proximate the chute to catch tableware inadvertently introduced thereinto. A scraper blade is formed to the cover proximate the chute such that food scraps scraped from plates and the like with the scraper fall through the chute and into the trash container.

Abstract: A method and apparatus for the fraction sorting of cells is provided. The invention include a dispensing device, aspirating device, flow channel and a magnetic assembly. A first fractional sorting device includes a dipole fractional cell sorter. The dipole fractional cell sorter includes large aspect ratio flow channel and a dipole magnetic assembly. A second fractional sorting device includes a quadrupole fractional cell sorter. The quadrupole fractional cell sorter includes an annular flow channel having inlet and outlet splitters, and a quadrupole magnetic assembly. The quadrupole magnetic assembly includes pole pieces having projecting members with convex surfaces and in is in physical communication with the annular flow chamber. The method of the present invention provides a flow through fractional cell sorting process which is based on the application of a magnetic force to cells having a range of magnetic labeling densities.

Abstract: A system and method for separating an electrically conductive particulate material, such as gold, from other materials. A ferromagnetic core is formed in a torroidal-like shape and is provide with a gap. A coil is wound around the core and an alternating current is applied to the coil to induce an alternating magnetic field at the gap. A stream of particles is directed into the gap. The frequency of the alternating current is set according to the specific resistivity of the particulate material which is to be separated from the rest of the material and according to the size of the particles which are to be separated from the rest of the material. By properly adjusting or setting the frequency of the alternating magnetic field, the first particles are imparted a trajectory which is different than the trajectory of the second particles in the particle stream.

Abstract: A process is provided for recovering a saline mineral from an ore containing the saline mineral and impurities. In one aspect, the process generally includes the steps of separating a first portion of impurities from the ore by density separation, electrostatically separating a second portion of impurities from the ore, and magnetically separating a third portion of impurities from the ore. The process can further include the steps of crushing the ore and dividing the crushed ore into a plurality of size fractions before the above-referenced separating steps. In another aspect, the process includes the steps of calcining the ore and subsequently separating a first portion of impurities by density separation. Indirect heating may be utilized for the calcining process and, preferably, calcining gases are recycled and utilized for heating fluidizing another portion of ore. Water vapor may be condensed from the calcining gas and utilized for other purposes.

Abstract: An ultrasonic energy source is used to provide a variable force for measuring the binding forces between molecular entities and for sensing the presence of an analyte in a test sample. The device includes a surface that has a first binding member attached thereto and one or more particles that have a second binding member attached thereto. A reaction vessel is provided for exposing the surface to the particles whereby, if the first binding member has a binding affinity for the second binding member, a complex is formed between individual first binding members and individual second binding members and the particles thereby become immobilized with respect to the surface. The ultrasonic energy source is positioned for applying a variable ultrasonic force onto the surface, and the position of the particles is monitored as the intensity of the ultrasonic force is varied.

Abstract: Shredder waste light fraction is converted into injectable material by being comminuted to an appropriate size. The copper and/or silica is then separated by magnetic separation so that the material may be injected into a metallurgical furnace or cement kiln.

Abstract: In an embodiment, a separating member is introduced into the compound, the member comprising a separating surface, the particles are pulled from the compound, by using a magnetic field, to be adhered to a separating surface, the effect of the magnetic field is eliminated, and the particles (16) are collected thereafter from the separating surface. In this way, it is possible to collect particles effectively even from a large volume. It is also easy to transfer particles into a small volume. The invention can be employed in various applications, especially in the fields of biotechnology, biochemistry, and biomedicine.

Abstract: An improved magnet configuration of the magnet field generated by the magnetic roller in a magnetic separator to increase the separation capability of magnetic separators includes disc shaped magnets forming a magnetic roller beneath a Kevlar.TM. belt upon which withdrawn catalyst is placed. Catalyst particles having paramagnetic and/or ferromagnetic properties are attracted to the belt because of the influence of the magnetic field. Particles not having ferromagnetic and/or paramagnetic properties are carried further by momentum than those with the ferromagnetic and/or paramagnetic properties. The magnetic roller provides a concentrated magnetic field by placing a series of disc magnets arranged so that like poles face each other with spacers placed between the magnets. In this stacked configuration the magnetic field strength is doubled, which permits a greater range of operation of the speed at which the belt may be operated.

Abstract: A method and system for separating, collecting and isolating radioactive metallic elements from low grade, dry, solid non-metallic nuclear bulk waste that includes physically degrading the low grade waste by shredding or grinding into small pieces, configuring the bulk waste into a waste stream, bombarding the waste stream with microwave energy at a preselected frequency treating the waste stream in a time varying magnetic field, causing the radioactive particles to disperse away from the bulk waste and collecting the separated micron sized radioactive particles. The present method and system provide for a low cost, non-complex system of separating out conductive radioactive particles from essentially non-metallic, dry, low grade nuclear waste allowing safe return to the environment of 95% to 99%, by volume, of the processed nuclear waste, greatly reducing the volume of nuclear waste that must be safely stored.

Abstract: Improvements in the existing procedures and materials for conduct of high gradient magnetic separation (HGMS) are disclosed. The use of plastic coated matrices especially small spheres or balls which form superior magnetic gradient-intensifying supports are disclosed, along with improved methods and apparatus to conduct HGMS. The selection of small spheres in combination with the coating provides for uniform matrices of high stability.

Abstract: A method of qualitative analysis of microscopic biological specimens is disclosed in which the specimens are rendered magnetically responsive by immunosspecific binding with feuromagnetic colloid. The specimens are placed in a vessel having a feuromagnetic capture structure supported on a transparent wall. The vessel is then placed in a magnetic field for inducing a high gradient region in the vicinity of the capture structure and, in particular, adjacent to the capture structure along the direction of the applied field. The magnetically responsive specimens are collected and immobilized by the high gradient along the wall adjacent to the capture structure for unobstructed microscopic observation. Subpapulations of distinct types of cells can thus be observed and differentiated. As transport force, such as gravity or an externally applied magnetic gradient, may be applied to the vessel to move the specimens into the high gradient region.

Abstract: Provided is a method of making improved brightness kaolin clay from an aqueous kaolin clay slurry in which the primary active dispersant is a weak dispersant, at least including the steps of adding to the kaolin clay an effective magnet enhancer reagent wherein the magnet enhancer reagent comprises an aqueous solution of one or more magnetic oxides and one or more surface active agents; conditioning the kaolin clay; and performing high gradient magnetic separation on the conditioned kaolin clay to produce an improved brightness kaolin clay. The method is also applied to decreasing iron- and/or titania-containing impurities in a clay.

Abstract: A method of quantitative analysis of microscopic biological specimens in a fluid medium is disclosed in which the specimens are rendered magnetically responsive by immunospecific binding with ferromagnetic colloid. A known quantity of magnetically-responsive marker particles are added to the fluid medium. The fluid medium is then subjected to a magnetic separation process, to collect the magnetic species from the fluid. The collected species are resuspended in a second fluid medium, and the relative quantities thereof are enumerated to determine the concentration of the desired biological specimen in the first fluid medium. The marker particles may comprise magnetic particles having a relatively large magnetic moment, a magnetic moment approximately equal to the magnetically-labelled biological speciment of interest, or both in order to compensate the determination for variations in immunospecific binding affinity and/or magnetic collection efficiency.

Abstract: The present invention relates to apparatus and methods for separating, immobilizing, and quantifying biological substances from within a fluid medium. Biological substances are observed by employing a high internal gradient magnetic capture structure formed within a vessel, in conjunction with an externally-applied force for transporting magnetically responsive material toward the capture structure. The invention is also useful in conducting quantitative analysis and sample preparation in conjunction with automated cell enumeration techniques.

Abstract: This method and apparatus for detecting target molecules in a liquid phase. The apparatus monitors whether the target molecule has selectively bound to recognition agents on the surface of a magnetic field sensor by monitoring the output of the sensor. The recognition agents which selectively bind target molecules are covalently bound to microfabricated magnetic field sensors. These sensors are then exposed to a sample suspected of containing the target molecules, whereupon the recognition agents bind to and immobilize any target molecules present. Depending on the embodiment, recognition agents that selectively bind the target molecule, or recognition agents that selectively bind the sensor-bound recognition agents, are covalently bound to magnetizable particles. These particles are then added to the sensors and, again depending on the embodiment, attach either to any immobilized target molecules or to sensor-bound recognition agents.

Abstract: An apparatus and method for immunomagnetic separation and concentration of target biological materials is disclosed. The immunomagnetic separation is performed by a magnetic flow cell, or filter block, as part of an automated mostly continuous immunomagnetic assay system. The magnetic flow cell has two bundles of ferromagnetic rods or pins positioned inside an internal chamber so that a fluid sample flowing through the flow cell passes through the pins. A pair of cobalt magnets flank the flow cell so that the pins concentrate and sufficiently increase the magnetic fields so that even nanometer size magnetic beads can be captured. The overall system combines a reaction subsystem for reacting coated magnetic beads with a sample, a collection subsystem for capturing magnetic beads, a rinsing subsystem for removing debris and a filtering subsystem for removing captured magnetic beads from the collection subsystem. The new magnetic flow filter is the key component for the collection and filtering subsystems.

Abstract: A method for separating cells is presented. The method provides a flow through fractional cell sorting process that is based on the application of a magnetic force to cells having a range of magnetic labeling densities. Magnetically labeled cells are introduced into a flow channel. The cells are continuously fractionated into flow streams based on magnetic susceptibility by subjecting the cells in the flow channel to a magnetic field. The fractionated cells are recovered based on their response to the magnetic field. Methods employing dipole fractional sorters and quadrapole annular sorters are also presented.

Abstract: The invention describes a process and an appliance for separating non-magnetic materials and objects with the use of magnetic fluids. With this invention a restoration of the magnetic fluid adhering to the separated material is made possible, by removing the magnetic liquid still adhering to the separated product both through magnets as well as through water. The magnetic fluid in the separating chambers is constantly monitored as regards volume and concentration via a monitoring installation. An appropriate area of use for the invention is the separation of fragmented materials, the separation of capacitors in capacitators containing polychlorinated biphenylenes (PCB) and PCB-free capacitors. The invention described, moreover, the composition, manufacture and use of environment-friendly diluted magneto-fluids, which can be especially suitable in employment in the separation of non-magnetic materials using the sink-float process in the magnetic field gradient.

Abstract: A method is disclosed for treating drilling mud discharged from a well wherein the mud contains drill cuttings and paramagnetic materials such as hematite. The drilling mud is first passed through a high-gradient magnetic separator to separate the paramagnetic materials from the drilling mud. The drilling mud is then passed through a centrifuge separator to remove the drill cuttings from the drilling mud.

Abstract: A process for the qualitative and/or quantitative determination of an analyte in a sample. The process includes providing a sample containing an analyte of interest in a liquid phase, providing at least one reagent having super-paramagnetic reactive metal particles linked to a substance that binds to the analyte, contacting the sample and the reagent to allow binding of the analyte in the sample and the reagent, applying a magnetic field to the mixture of sample and reagent, and detecting the presence of the analyte in the sample. The device includes a support for the sample and reagent, means for contacting the sample and reagent, magnetic means for confining and separating the analyte from the other components of the sample, and detection means for qualitative and/or quantitative measurement of the analyte.

Abstract: A mixture of electronic component chips 2 and media 3 is placed in a planar state on a transport surface 4 of a conveyor 5. Only the media 3 are collected onto a first circulating circumferential surface 18 by a magnetic force provided by a first collection member 12 and are thereafter collected by a media collecting box 22. Then, only electronic component chips 2 having a plating film of a proper thickness formed thereon are attracted onto a second circumferential surface 28 by a magnetic force provided by a second collection member 23 and are thereafter collected by a good product collecting box 31. Electronic component chips 2a having a plating film of an insufficient thickness formed thereon are collected by a defective product collecting box 32.

Abstract: Method and apparatus for enabling resuspension wash and magnetic localization of sample components bound to particles with magnetic properties in reaction vessels during separation and wash for enhanced chemiluminescent signal generation in biomedical assays. The assays involve moving reaction vessels past magnetic arrays that partially localized the particles prior to passing a gap where washing occurs, with or without resuspension, after separating out the unbound components and liquid. The band of particles is further localized by a focusing magnet at the end of the array prior to dosing the vessel with acid for chemiluminescent purposes. A block of soft magnetic material is employed in place of a magnet in the gap to minimize magnetic strength at the gap. Trimmed magnets adjacent the gap cause left, then right, particle shifting that localizes the magnetizable particles. The gap enables improved resuspension by wash, whereas the localized particles enable more efficient resuspension by reagent.

Abstract: A magnetic ore purification system for enriching magnetic ore concentration in a feed material. The system includes an elutriator, an alternating current magnet, and an ultrasonic separator. The elutriator has a feed port for introducing the feed material into the elutriator and an enriched material port for collecting an enriched material having a magnetic ore concentration that is greater than the feed material. The alternating current magnet generates a uniform low strength magnetic field within the elutriator. The ultrasonic transducer introduces ultrasonic energy into the elutriator.

Abstract: A species such as a microorganism, e.g. Legionella, Giardia or Cryptosporidium, is captured by first attracting plastic coated magneticbeads or other magnetically attractable particles to a solid support such as stainless steel mesh, which particles have a selective affinity for the species, e.g. by virtue of an antibody coating, and contacting a sample containing the species with the particles on the solid support. The beads bearing the captured species may be released by reduction of the magnetic attraction of the support for the beads, e.g. by turning off an electromagnet used to magnetize the support.

Abstract: A system and method for separating an electrically conductive particulate material, such as gold, from other materials. A ferromagnetic core is formed in a torroidal-like shape and is provide with a gap. A coil is wound around the core and an alternating current is applied to the coil to induce an alternating magnetic field at the gap. A stream of particles is directed into the gap. The frequency of the alternating current is set according to the specific resistivity of the particulate material which is to be separated from the rest of the material and according to the size of the particles which are to be separated from the rest of the material. By properly adjusting or setting the frequency of the alternating magnetic field, the first particles are imparted a trajectory which is different than the trajectory of the second particles in the particle stream.

Abstract: A method for determining an analyte in a sample which includes: providing the sample in liquid phase, the analyte of which has a ligand having at least one anti-ligand specific recognition site; providing at least one reagent containing metal particles, in suspension in liquid phase and non-separable from the liquid phase by a magnetic or electromagnetic force, each particle containing a metal core to which at least one anti-ligand is fixed directly or indirectly; contacting the sample and the at least one reagent in order to obtain metal clusters; placing the metal clusters in a magnetic field generated by a magnetic or magnetic field generating sensor in order to assemble the metal clusters; and detecting the assembled metal clusters to obtain a signal representative of the mass of metal in the clusters, which is correlated with the quantity of analyte present in the sample initially. A device for determining an analyte in a sample by the above process is also included.

Abstract: A method and apparatus for separating solid supports formed of magnetic particles on which immunocomplexes are bound, from a liquid phase includes a reaction container containing a fluid in which magnetic particles having immunocomplex bound thereon are suspended. The reaction container is positioned at a flock forming station, where the fluid is subjected to an alternate current magnetic field having a temporally varying intensity by an electromagnetic. The magnetic particles are flocculated with each other due to the application of such varying magnetic field to form a multiplicity of flocks. A stronger magnetic field then is applied to the resulting contents in the reaction container by a permanent magnet. The flocks are magnetically fixed on the inner wall surface of the reaction container by the action of the stronger magnetic field.

Abstract: A method and apparatus for determining qualitatively or quantitatively the presence of analyte bound to a separation media without doing a bound/free separation. In the method, the bound fraction is collected in an assay region of a body of liquid which includes the free analyte, and the assay is performed by comparing the radiant-energy response in the assay region to the radiant-energy response in a control region of the body of liquid which is free of bound analyte. The apparatus has a chamber which contains the body of liquid, one or more collection elements and a control element and position in the body of liquid parallel to an opaque wall which has a colliminating slit in registry with each element. Each slit enables sensing of the radiant-energy response from the body of liquid between the slit and its associated elements.

Abstract: A method for removal of magnetic ink from pulp stock formed from xerographic and laser printed paper waste comprising feeding such pulped paper waste past one or more magnets for removal of all or substantially all of such magnetic ink. The magnetic ink can be removed by capture or deflection techniques. The preferred pulp slurry has a concentration of 4% or less by weight pulp. The preferred magnetic force to be applied utilizes background magnetic fields in excess of 2000 Gauss and a field gradient in excess of 500 Gauss/cm. Also, a method for improving the recyclability of paper waste having ink thereon which does not normally contain a magnetic component, by utilizing one or more magnetic carriers in the formulations of the printing ink utilized.

Abstract: A method of recovering a first material, e.g. plasmid DNA, from a solution containing pre-precipitated second material, e.g. genomic DNA and cellular debris, by precipitating the first material in the presence of magnetically attractable beads which become non-specifically associated with the newly formed precipitate, using a magnet to draw down the beads and the newly formed precipitate, and removing the supernatant.

Abstract: A method for determining the presence and/or concentration of a target substance e.g. protein, nucleic acid, bioparticle etc. in a fluid sample is provided. The method disclosed combines elements of immunoassays, coated cup assays and magnetic particle separation to effect the quantitation and recovery of an analyte in solution. Also the method ensures the non-reorientation of magnetically collected material by linking the magnetic particles to a collection surface via a specific binding pair. This linkage immobilizes the magnetic-analyte-containing material and thus allows for vigorous washing and reagent addition without significant redistribution or displacement. Thus the assay of this invention offers the speed of diffusion controlled kinetics as in a ferrofluid assay, the speed of collection of labeled target substance as in a magnetic assay as well as the ability to magnetically monolayer the ferrofluid, all of which is combined with the ease of washing and signal detection found in a coated cup assay.

Abstract: It is often important for medical purposes to obtain nucleated fetal cells during pregnancy. For example, the procedures of amniocentesis or chrionic villae extraction are carried out for this purpose. But these methods are invasive, and carry a small but positive risk to the patient, and are complicated to perform. On the other hand, the purpose of my invention is to obtain nucleated fetal cells (fetal nucleated reticulocytes) from maternal blood, which eliminates the need for invasive methods. There are a small number of nucleated fetal red blood cells (reticulocytes) in maternal blood and my invention is a method and apparatus for separating these fetal cells from maternal blood.

Abstract: A method and apparatus for automated separation of fluid borne magnetically responsive spheres into different populations by carefully manipulating forces of gravity, buoyancy, fluid friction, and magnetism. Distinct homogeneous sphere populations are separated from a non-homogeneous population including a plurality of intermixed homogeneous sphere populations, without significant manual processing, by: effecting magnetic distancing of an initial non-homogeneous sphere population; facilitating enhanced separation of the non-homogeneous population in accordance with rate of descent of spheres within homogeneous populations; providing magnetic acceleration of the separation process; and effecting magnetic concentration of the separated homogeneous sphere populations. The process and apparatus provide for improved bio-sensing resulting from the automated condensing of homogeneous groups of spheres from a non-homogeneous sphere population.

Abstract: A process for removing iron impurities, inter alia iron or iron compounds, from petroleum oil distillation residues is disclosed in which a high gradient magnetic separator incorporates a pack of ferromagnetic fillers in the form of a generally flat or curved sheet-like strip. The ferromagnetic filler is a Fe--Cr alloy of a selected composition and the strip is of selected geometric characteristics such that the rate of removal of iron impurities can be maintained substantially at a maximum throughout the separation mode of operation prior to and after washing of the ferromagnetic filler.

Abstract: An apparatus and method provide automated collection and transfer of particles from a liquid suspension to a glass slide for visual examination. A magnet is positioned adjacent to a solution which contains particles tagged with magnetic beads, for example cells, so that the magnetic particles flow toward the magnet and collect against a collection surface positioned between the particles and the magnet. A transfer mechanism applies a selected pressure to a second side of the collection surface for transferring collected cells to a viewing slide. The apparatus includes a device for dispersing the liquid suspension of particles prior to the collection process and for collecting particles against the collection surface with a spatial distribution advantageous for visual examination. The transfer operation maintains this spatial distribution.

Abstract: Magnetic separations are made by feeding material to a magnetic separator having elongated ferromagnetic bodies that are disposed parallel to each other with spaces therebetween, the bodies being disposed at an angle to the magnetic field direction. The magnetic particles are deflected away, while the nonmagnetic particles pass through the spaces between the ferromagnetic bodies. In one embodiment, the separator includes a magnetic circuit including an array of elongated ferromagnetic bodies, parallel to each other with spaces therebetween, and on the same side of a common tangential plane that is positioned substantially perpendicular to the direction of the field created by the magnetic system and at an acute angle to the direction of particle feed towards the ferromagnetic bodies.

Abstract: A magnetic separator (2) for separating magnetic particles from a passing slurry material comprises a canister (22) having a paramagnetic matrix element (24) disposed therein. Inlet and outlet manifold assemblies (30, 32) are disposed on either side of the canister for directing the slurry through the matrix element. Diffusers (60), positioned between the inlet and outlet manifold assemblies and the matrix element, comprise a hollow conical body (62) with a narrow inlet (64) facing the inlet manifold and an enlarged outlet (66) facing the matrix element. The diffusers define inner and outer flow passages for the slurry so as to distribute the slurry over a large portion of the paramagnetic matrix element, thereby avoiding localized saturation of the matrix element and increasing the on line time of the apparatus.

Abstract: Improvements in the existing procedures and materials for conduct of high gradient magnetic separation (HGMS) are disclosed. Superior superparamagnetic particles, optionally coated with a polysaccharide or other, usually organic, materials can be prepared in uniform compositions with homogeneous magnetizations. The coating can conveniently be conjugated to a specific binding moiety complementary to a biological material whose purification or separation is desired. In addition, plastic coated matrices which form superior magnetic gradient-intensifying supports are disclosed, along with improved methods and apparatus to conduct HGMS.

Abstract: Methods and devices are provided for separation of magnetic particles and/or magnetic-associated substances from non-magnetic associated substances and media. The methods are specifically applicable to biological separation, and utilize a phase phenomenon arising from mutual interactions between suspended magnetic particles and interactions with the suspension medium. The phenomenon is exploited to produce and maintain a distinct, structured phase of magnetic particles, or ferrophase, within a multi-phase liquid system. A ferrophase is established within a separation chamber prior to introducing therein a test sample containing the target substances to be separated. The formation of a ferrophase is used to transport target substances from regions of relatively low magnetic field gradient to regions of relatively high magnetic field gradient within a high-gradient magnetic separation apparatus.

Abstract: A method is disclosed for separating a substance from a liquid medium. The method comprises combining the liquid medium containing the substance with magnetic particles under conditions for non-specific chemical binding of the magnetic particles. Thereafter, the medium is subjected to a magnetic field gradient to separate the particles from the medium. The preferred non-specific binding is achieved as the result of charge interactions between the particles usually by means of a polyionic reagent. The method of the invention has particular application to the separation of cells and microorganisms from aqueous suspensions and also to the determination of an analyte in a sample suspected of containing the analyte. The analyte is a member of a specific binding pair (sbp). The sample is combined in an assay medium with magnetic particles and a sbp member complementary to the analyte.