Apparatus and method for analyzing particles suspended in a liquid

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette, said elongated flow area constituting a capillary passage;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative t one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated grove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• and
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area;
• and
• said electrodes being embedded within said first or second body member providing exposed electrode surfaces at said elongated flow area.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• said mean for exposing said fluid medium to said radiation being constituted by a light source.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area;
• and
• said means for exposing said fluid medium to said radiation being constituted by a light source.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area;
• said means for exposing said fluid medium to said radiation being constituted by a light source, said light source generating light which is focused at a specific area of said elongated flow area;
• said electrodes and said specific area being arranged in succession relative to said first direction;
• and
• said electrodes being arranged upstream relative to said specific area.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• p1 said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area;
• said means for exposing said fluid medium to said radiation being constituted by a light source, said light source generating light which is focused at a specific area of said elongated flow area, said electrodes and said specific area being arranged in succession relative to said first direction;
• said electrodes being arranged upstream relative to said specific area;
• said light source being constituted by a flash;
• and
• a control means connected to said electrodes and to said flash for controlling the operation thereof in response to the detection of the particle passing through said electrical field so as to expose said particle to said light from said flash.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area;
• said electrodes being embedded within said first or second body member providing exposed electrode surfaces at said elongated flow area;
• said electrodes and a specific area of said elongated flow area being arranged in succession relative to said first direction;
• said electrodes being arranged upstreams relative to said specific area;
• means for exposing said fluid medium to said radiation constituted by a light source being further constituted by a flash;
• and
• a control means connected to said electrodes and to said flash for controlling the operation thereof in response to the detection of the particle passing through said electrical field so as to expose said particle to said light from said flash.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• an agitating means constituted by a wire and a wire rotating means, said wire being arranged extending through said means for feeding said fluid medium to said elongated flow area and at least partially into said elongated flow area, said wire being rotated relative to its rotational axis by means of said wire rotating means so as, to any substantial extent, to eliminate the risk of blocking said feeding means and said elongated flow area.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• a means for feeding a diluent to said elongated flow area.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• at least two electrodes for generating an electrical field through which said fluid medium is passed when guided through said elongated flow area;
• said means for exposing said fluid medium to said radiation being constituted by a light source, said light source generating light which is focused at a specific area of said elongated flow area;
• said electrodes and said specific area being arranged in succession relative to said first direction;
• said light source being constituted by a flash;
• a control means connected to said electrodes and to said flash and controlling the operation thereof in response to the detection of the particle passing through said electrical field so as to expose said particles to said light from said flash;
• a means for feeding a diluent to said elongated flow area;
• means for controlling the supply of said diluent to said elongated flow area and;
• said means for controlling the supply of diluent to said elongated flow area being connected to and being controlled by said control means.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• a flow control means for controlling the flow of said fluid medium through said elongated flow area.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• a spring-loading means actuating at least one of said body members by a spring force perpendicular to said facial surfaces of said body members.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• a means for conducting a rinsing liquid to said planar facial surfaces of said body members when said body members are in said second position.

An apparatus for analyzing particles suspended in a fluid medium, said particles being capable of emitting radiation characteristic of said particles when exposed to radiation, and comprising:

• a cuvette, in which an elongated flow area having the shape of a passage is provided for guiding said fluid medium in a first direction through said elongated flow area of said cuvette;
• means for feeding said fluid medium to said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for discharging said fluid medium from said elongated flow area;
• means for exposing said fluid medium to said radiation in a second direction defining an angle relative to said first direction;
• means for picking up at least part of said radiation characteristic of said particles and emitted by said particles when exposed to radiation;
• said cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface;
• said first and second body members being movable relative to one another between a first position, in which said planar facial surfaces are positioned closely adjoining one another, and a second position, in which said planar facial surfaces are positioned spaced apart;
• at least said facial surface of said first body member being provided with an elongated groove defining together with said adjoining facial surface of said second body member said elongated flow area having the shape of said passage when said body members are in said first position;
• said means for feeding said fluid medium to said elongated flow area comprising an inlet provided in one of said body members and extending from the exterior relative to said cuvette to an inlet aperture of said elongated flow area;
• said means for discharging said fluid medium comprising an outlet provided in one of said body members and extending from an outlet aperture of said elongated flow area to the exterior relative to said cuvette;
• at least one of said body members being transparent to said radiation to which said fluid medium is exposed and to said radiation emitted by said particles;
• and
• said apparatus being adapted to carry out a flow-cytometrical analysis of fluorescent particles, in particular the size of the particles is within the range of approximately 8-15 .mu.m.