Coulter Electronics, Inc.

Other

Marshall D Graham

Dudley D Cook, Jr

F Robert Drury

Robert Shaw

Donald L Gecks

William A Newton

David D Cook, Jr

William G Graham

An apparatus for dislodging fragile particles, such as intact biological cells, retained by the separation matrix in a flow chamber of a magnetic separation system. The apparatus incorporates a piezoelectric transducer which is coupled to the matrix and an associated drive circuit. The system can operate in a capture phase, whereby fragile particles are selectively captured from a carrier fluid passing through the matrix, with those captured particles being magnetically held in place within the matrix. In the elutriation phase, an elutriation fluid is passed through the matrix and the drive circuit excites the piezoelectric transducer. In response to the excitation, the transducer establishes acoustic waves in the elutriation fluid passing through the matrix, vibrating the matrix itself. Depending upon the mechanical impedances within the flow chamber, the acoustic waves can be ultrasonic. The acoustic waves and matrix vibration operate to dislodge the intact cells from the matrix, even at relatively low elutriation flow rates.

Apparatus for acoustically removing particles from a magnetic separation

A system for the magnetic separation of fragile particles, such as intact biological cells, from a fluid medium. The system includes at least one high-gradient magnetic separator having a flow chamber housing an interstitial separation matrix and associated magnetizing apparatus for coupling magnetic flux to the matrix. The matrix has interstices through which a carrier fluid carrying the cells-to-be-separated may be passed. The magnetizing apparatus includes opposing North and South poles and field-guiding pole pieces, external to the flow chamber. The flow chamber comprises a dual-position flux-coupler. The flux-coupler is operative in a first position in the capture phase and in a second position in an elutriation phase. In the capture phase, the flux-coupler is positioned to permit the magnetic flux from one magnetic pole to pass through the matrix to the other magnetic pole. As the carrier fluid flows through the interstices of the matrix in this phase, particles, such as blood cells, in the input fluid are retained in the matrix, where magnetic forces dominate gravitational and viscous forces. In the elutriation phase, the flux-coupler is positioned so that magnetic flux is diverted from the matrix. In this phase, magnetic flux is greatly reduced in the matrix, permitting viscous forces to the fluid to remove the magnetic particles from the matrix at low flow velocities.

Flux diverting flow chamber for high gradient magnetic separation of

An optical microscope system includes an optics system and a frame. A selectively controlled stage assembly is coupled to the frame by vacuum-retained air-bearings. An air vacuum chuck coupled to the stage selectively aligns and supports an object-bearing slide for viewing with the optics system.

Optical microscope system

A portable, manually operable device for preparing a monolayer film of a biological fluid sample or the like on a slide for microscopic examination. Said device includes a base for retaining the slide thereon and a spreader manually movable linearly relative to the base and slide in a pass which spreads a sample of the fluid on the slide into such a monolayer. Preferably, the spreader is constructed to be disposable.

Slide preparation apparatus

A microscopy system for automatically locating and re-locating objects-of-interest in an image which has one or more objects against a background. Each of the objects-of-interest is characterized by a predetermined set of features. In a preferred form, the invention is specifically directed to an automated microscopy system which is adapted for automatically analyzing biological (e.g., blood or cervical) cells on microscope slides. In other forms of the invention, differing types of objects may be identified as being objects-of-interest during a first automated pass and then re-located during a second pass for further analysis.

Automated microscopy system and method for locating and re-locating

An air vacuum chuck for a microscope includes a body member having a planar slide-supporting surface. Stop members are adapted to align a slide in a predetermined orientation. Air ports and vacuum ports in the slide-supporting surface selectively couple a relatively high pressure air reservoir and a vacuum reservoir, respectively, to the region between the slide-supporting surface and the object-bearing surface of the slide. The air ports are adapted to provide airflow directed towards at least one of the stop members. In an alignment mode, airflow from the air ports and vacuum from the vacuum ports establish a vacuum-retained air-bearing with a substantially frictionless coupling between a slide and the slide supporting surface. The vacuum from the vacuum ports controls the separation between the slide and the slide-supporting surface. The directed airflow imparts a net force on the slide, positioning the slide against the stop members. In a support mode, vacuum from the vacuum ports retains the slide with its object-bearing surface held against the slide-supporting surface.

Air vacuum chuck for a microscope

Disclosed is a new method for magnetic separation from a carrier fluid of biological cells or other organic or inorganic particles having a negative surface charge. A paramagnetic salt is mixed with an aqueous solution of a chelating agent, for example EDTA. The cells or particles to be separated are mixed with this paramagnetic carrier solution, and the resulting mixture is exposed to a high gradient magnetic field. The cells or particles attract the chelated paramagnetic cations preferentially to the carrier solution such that the particles develop a magnetic susceptibility greater than that of the carrier liquid. The method achieves highly repeatable separations at lower magnetization fields than existing high gradient magnetic separation methods. Feasibility has been shown for erbium chloride and dysprosium chloride, with whole blood as the sample. In this instance, single-pass magnetic separation efficiencies significantly greater than those attainable with paramagnetic erythrocytic hemoglobin are readily available.

Magnetic separation using chelated magnetic ions

A particle analyzer wherein a flow of liquid suspension, having individually entrained particles, flows along a predetermined path; a center pair of electrodes are positioned on opposed sides of the predetermined path: the center electrodes are energized to provide an electrical sensing field therebetween, two pairs of outer electrodes are positioned so that one pair is on each side of the center electrodes; the outer electrodes are oriented and/or energized so that their electrical fields bulge outward in the direction of the sensing field of the center plates to narrow the width of the sensing field along the predetermined path. Additionally, the field between the center plates can be focused in additional directions and the sensing electrode arrangement can be implemented in a flow cell, with or without an aperture, or on the surface of a substrate.

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Framingham, MA, United States of America

Marshall D Graham