Coulter Electronics, Inc.

Coulter Corporation

Robert E Auer

Wallace H Coulter

Raul I Pedroso

James C Wood

Bruce M Weber

Howard E Tucker

John D Starling

A flow cytometer includes a plurality of detectors for providing voltage pulse signals over a four decade range as particles pass through an illuminated detection station. Each voltage pulse signal is processed and provided to a first sample and hold for storage. Thereafter, the value in the first sample and hold is amplified by one or thirty-two, depending upon its magnitude, and stored in a second sample and hold for subsequent provision to a sixteen bit analog to digital convertor (ADC), one signal at a time. The first sample and hold is then free to store a new value while the old value is awaiting provision to the ADC. The ADC converts the signal received from the second sample and hold to a fifteen bit digital signal and uses the sixteenth bit to manifest whether the signal stored in the second sample and hold was amplified by thirty-two.

Flow cytometer

A coincidence arbitration system for a sorting cytomteter which detects and sorts particles using a flow chamber and a stream of droplets. Those droplets containing selected particles are sorted by selectively applying a charge thereto and passing the droplets through deflection plates. After detection, the particle data is delayed and analyzed to make sort decisions. The delay is for a period of one and one fourth droplet time periods less than the time the particle is formed into a droplet. At the time the command is issued creating the charge on the droplet to be formed, the coincidence arbitration circuit looks four quarter droplet times ahead and behind of the event to determine whether a coincidence is occurring, and if so, whether the coincidence is with a similar type of particle or a different type of particle. Based on this information, appropriated sort or no-sort commands are issued.

Coincidence arbitration in a flow cytomery sorting system

A particle separator for sorting particles suspended in a liquid according to certain characteristics, including a method of and apparatus for detecting a change in the droplet breakoff point of a liquid jet stream which is subjected to vibrations. The vibrations produce amplitude undulations on the surface of the jet stream. The amplitude of the undulations is monitored or interrogated at a fixed point on the jet stream prior to the breakoff point. A change in amplitude of the undulations at that fixed point produces a signal voltage at a masked sense diode the value of which is proportional to the amplitude change. This signal voltage may be used (1) to alert the operator that a change has occurred in the point at which the jet stream is breaking up into droplets, (2) to automatically control the intensity of the vibrations for restoring the amplitude of undulation at that fixed point to its original state, or (3) to automatically disable the sorting portion of the apparatus. Any one or any combination of the foregoing three happenings can be utilized.

Method of and apparatus for detecting change in the breakoff point in a

Flat beam optical sensing performed transverse of a flow aperture, of the particles passing through the aperture, directly indicates the presence of individual particles in the aperture. The indication can be used to eliminate or otherwise modulate the coincidence errors resulting in particle measurements taken through the length of the aperture.

Coincidence correction in particle analysis system

A particle separator for sorting particles suspended in a liquid according to certain characteristics, including a method of and apparatus for detecting a change in the droplet breakoff point of a liquid jet stream which is subjected to vibrations. The vibrations produce amplitude undulations on the surface of the jet stream. The amplitude of the undulations is monitored or interrogated at a fixed point on the jet stream prior to the breakoff point. A change in amplitude of the undulations at that fixed point produces a signal voltage the value of which is proportional to the amplitude change. This signal voltage may be used (1) to alert the operator that a change has occurred in the point at which the jet stream is breaking up into droplets, (2) to automatically control the intensity of the vibrations for restoring the amplitude of undulation at that fixed point to its original state, or (3) to automatically disable the sorting portion of the apparatus. Any one or any combination of the foregoing three happenings can be utilized.

An apparatus and method for illuminating particles, wherein a source of illumination provides a beam of illuminating radiation which perpendicularly intersects a stream of liquid having the particles suspended therein. The illuminator apparatus comprises a concave reflector surface having a center of curvature and an optical axis which is disposed perpendicularly relative to the stream and with the beam being positioned thereon. The stream of liquid defines a cylindrical lens having a focus positioned at the center of curvature. In operation, the illuminating radiation illuminates the particles, is refracted by the stream so as to converge to a focus, passes from that focus to a concave reflector surface, and reflects from the concave reflector surface back to the focus, so as to impinge upon the stream for a second time, to further illuminate the particles.

Reflector for the laser beam of a particle analyzer

The containment of biohazardous substances, which may exist in the streams of sample material that are being separated in air into droplets in a testing chamber of equipment, such as cell sorters and cytofluorometers, is attained by subjecting the testing chamber to negative air pressure, so that inward air flow at the open face of the chamber is sufficient to inhibit biohazardous substances from exiting out from the face of the chamber. A region of air stagnation is created around the sample streams so that the streams are not deflected from their paths, such paths being pertinent to their testing of the biological sample material. The air stagnation region is formed by interposing an air diverter between the sample streams and the air flow exhaust port at the rear of the testing chamber.

Biohazard containment apparatus and method

A method and apparatus for simultaneous optical measurement of several characteristics of each particle of a group of small particles while the particles are suspended in a liquid. The apparatus includes a sample passage structure through which the particles pass, and a first optical detector structure which receives light from the sample passage structure. The sample passage structure and detector are aligned one with respect to the other. The output of a source of light is directed to the sample passage structure by an alignment device which aligns the light and the sample passage structure. A second optical detector receives the light passed by the sample passage structure. The second detector includes a converging lens and a photodetector so positioned with respect to one another that the light pattern at the detector due to the passage of a particle through the sample passage structure will maintain a substantially constant intensity notwithstanding movement of the sample passage structure, particle or the light.

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Miami, FL, United States of America

Robert E Auer