Coulter International Corp.

Beckman Coulter, Inc.

Marshall Donnie Graham

Mark A Wells

Jose M Cano

James P Clarkin

Carlos Alberto Arboleda

William Gerry Graham

Armando Jose Sanchez

Gary L Dorer

Harvey J Dunstan

Daniel Dashui Gao

Ted W Britton

Manuel Calvo

Cynthia J Sperber

John Geoffrey Harfield

Gerry Graham

James S King

Armando J Sanchez

An improved optical flow cell adapted for use in a flow cytometer for differentiating formed bodies (e.g., blood cells) in liquid suspensions. Preferably manufactured by assembling, aligning, and optically joining at least two elements made from transparent material, the improved flow cell has a seamless internal flow channel of preferably non-circular cross-section in a cylindrical first element through which prepared samples can be metered and an independent second element having an external envelope suited to acquisition of optical parameters from formed bodies in such suspensions, the second element being conforming and alignable to the first element so that non-axisymmetric refractive effects on optical characterizing parameters of formed bodies passing through the flow channel in the first element may be minimized before the two elements are optically joined and fixed in working spatial relationship.

Compound optical flow cells and method of manufacture and use

Systems and methods are provided for sensing and characterizing small particles, and in particular blood cells suspended in a liquid medium. Exemplary systems include a volumeter conduit having a central region of higher electrical resistivity disposed between a first and second distal region of lower electrical resistivity, and a current source and sensing circuit module in electrical connectivity with the first and second distal regions. The module provides an electrical excitation current to the first and second distal regions to establish a particle-sensitive zone within the conduit, and detects current changes occasioned by particles of the biological sample passing through the particle-sensitive zone.

Systems and methods for particle sensing and characterization

An improved optical flow cell adapted for use in a flow cytometer for differentiating formed bodies (e.g., blood cells). Manufactured from a monolithic transparent material, the improved flow cell has an internal flow channel of polygonal transverse cross-section through which prepared samples can be metered and an external envelope suited to acquisition of optical parameters from formed bodies in such samples. Preferably, such flow cell is formed by a glass-drawing process in which a relatively large glass preform having a rectilinear internal channel of a desired polygonal cross-sectional shape is heated and drawn to achieve a desired cross-sectional area of reduced size. Also disclosed are preferred methods for differentiating formed bodies using the flow cell of the invention.

Monolithic optical flow cells and method of manufacture

Environmentally stable amorphous silicon photoreceptor and method for making same

Apparatus for sensing and characterizing particles suspended in a liquid medium includes a particle-sensing structure having a continuous wall defining a hydrodynamically smooth conduit through which the liquid suspension of particles is caused to pass simultaneously with an electrical current. Particles passing through the conduit are sensed and characterized by monitoring changes in the electrical current through the conduit. According to the invention, the continuous, conduit-defining wall is made entirely of a material having an electrical resistivity less than or equal to that of the liquid medium. Thus, the apparatus of the invention is similar to the conventional Coulter aperture (conduit) except that the aperture is formed from an electrically conductive material instead of a dielectric material.

Apparatus incorporating a sensing conduit in conductive material and method of use thereof for sensing and characterizing particles

A new photoreceptor is provided which comprises a conductive substrate and a photoconductive layer of 5 micra or less in thickness on the substrate. The photoreceptor has a dark decay greater than 20 seconds and contains less than 5% total hydrogen. The substrate is selected from the group consisting of alloys of aluminum, chromium, iron, molybdenum, nickel or tungsten. In addition, the substrate can be a nonconductive material, such as plastic, provided with an electrically conductive layer. A new method for making the improved photoreceptor comprises providing a conductive substrate and forming a photoconductive layer of 5 micra or less in thickness on said substrate by depositing an amorphous material containing silicon and hydrogen atoms wherein said substrate has a negative potential between &minus;40 and &minus;100 volts during the forming of said layer.

Amorphous silicon photoreceptor and method for making same

A Coulter apparatus comprises a volumeter assembly containing a conduit through which a particle suspension is caused to pass simultaneously with an electrical current. In preferred embodiments the volumeter assembly comprises at least one traditional Coulter conduit wafer, i.e., a dielectric wafer containing a central circular conduit, and at least two electrically conductive collars. The conductive collars approximate the conduit diameter in thickness, are uninsulated, and are attached to opposite sides of the conduit wafer, the openings being congruent with the Coulter conduit. The Coulter conduit in the dielectric wafer and the openings in the conductive collars collectively form a hydrodynamically smooth conduit, in which the electric and hydrodynamic fields of the Coulter conduit are amended. The electric field is shaped to confine the particle-sensitive zone of the novel volumeter conduit within the conduit's physical boundaries, thereby decreasing the zone's coincidence volume. The hydrodynamic field is caused to develop quasi-laminar flow, thereby increasing the proportion of particles per second transiting the zone's electrically homogeneous areas. The conductive collars are provided with electrical connections and also function as electrodes, used either in a passive mode to allow potential-sensing of particle characteristics or in an active mode in response to such particle characteristics. The volumeter assembly substantially eliminates need to compensate for the effects of particles either transiting the sensitive zone on trajectories near the conduit wall or recursing through the exit portion of the particle-sensitive zone.

Potential-sensing method and apparatus for sensing and characterizing particles by the Coulter principle

Apparatus for sensing and characterizing particles (e.g., blood cells or ceramic powders) suspended in a liquid medium comprises a conduit through which the particle suspension is caused to pass simultaneously with an electrical current. According to the invention, the interior wall of the conduit effectively varies in resistivity along the length of the conduit to define a delimited central region of high electrical resistivity which is smoothly contiguous on its opposing boundaries to uninsulated distal elements of lesser electrical resistivity. The delimited central region of the conduit functions as a Coulter volumeter conduit. The uninsulated distal elements of the conduit are made to have a dimension along the conduit wall which is at least equal to the axial extent of the effective ambit electric fields of a traditional Coulter volumeter conduit having a cross-sectional geometry identical to that of the delimited central region of high resistivity in the improved volumeter conduit. According to a preferred embodiment of the invention, the delimited central region of the improved volumeter conduit is defined by a traditional Coulter conduit wafer, i.e., a dielectric wafer containing a central circular conduit, and the distal elements of lesser resistivity are defined by uninsulated, electrically conductive, circular collars attached to opposite sides of the conduit wafer. The conduit in the conduit wafer and the openings in the conductive collars collectively form a hydrodynamically smooth volumeter conduit, in which the electric and hydrodynamic fields of the traditional volumeter conduit are advantageously amended in the manner above noted.

Method and apparatus for sensing and characterizing particles

Apparatus for drying a succession of microscope slides having wet blood specimen smears on a first major surface, including a belt transport for moving slides along a longitudinal drying path with their wet surfaces facing in a common direction and means for directing low velocity, heated air flows toward the non-smeared, major slide surfaces. Air flow proximate the slides preferably is about 15.degree. C. above ambient and at a velocity of about 10 to 30 feet per minute for a drying period of about 75 to 135 seconds, per slide.

Apparatus for drying blood smear slides

A blood analyzer system is provided with improved slide making capability by coupling a blood analyzer apparatus to an automatic slidemaking apparatus by means of a clinically effective blood specimen transport assembly, which includes a blood conduit forming a curvilinear flow path that imparts a substantial angular velocity component to blood moving therein. The system enables a blood analyzer portion and a smear slide portion of a given sample to be aspirated with physical and temporal proximity.

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Nicholasville, KY, United States of America

Marshall Donnie Graham