Gesellschaft Fur Strahlen- Und Umweltforschung Mbh, Munchen

Gesellschaft Fur Strahlenund Umweltforschung Mbh

Wolfgang G Eisert

Wolfgang Beisker

Arrangement for measuring the fluorescence polarization of cells or particles which are aligned individually along a flow stream illuminated by means of an illumination field wherein the cells are passed in succession through two light beams so as to excite fluorescence; the directions of polarization of the two excitation beams are perpendicular to one another; a pair of detector channels are provided to successively record the two polarization components of the fluorescence at both points of excitation; and an analysis system is provided which calculates the corrected degree of fluorescence for the individual cells from the measured values provided by the detector channels.

Arrangement for measuring fluorescence polarization

In apparatus for measuring reaction and/or diffusion of particles suspended in a fluid, which apparatus includes a supply tube for supplying a stream of the particle-containing fluid, a tapered tube surrounding the supply tube for providing a first entraining fluid stream and for encasing the particle-containing fluid in the first entraining fluid stream for the purpose of hydrodynamically focusing the particle-containing stream into a thin stream enclosed by the first fluid and in which the particles are separated from one another, an outlet for passage of the thin stream and first fluid stream after leaving the tube, a device producing a radiation beam which intersects the thin particle-containing stream, a detector disposed for detecting the radiation emanating from the separated particles, and a pulse evaluation circuit connected to the detector, there is provided a further tube surrounding the supply tube and forming a further entraining fluid stream concentric with the particle-containing stream and the first entraining fluid stream, surrounding the particle-containing stream and flowing therewith through the tapered tube, the further entraining fluid stream having a composition selected to interact with the particles.

Apparatus for measuring particle characteristics

An apparatus for hydrodynamically focusing particles to permit counting and classification of the particles, which apparatus includes a flow nozzle terminating in a capillary nozzle that forms a thin stream containing the particles and having a circular cross section with the particles oriented along one axis of the thin stream, and a jacket pipe enclosing the capillary nozzle for providing an entraining stream for the thin stream of particles leaving the capillary nozzle, is further provided with a further flow nozzle located downstream of the capillary nozzle and presenting a circular cross section for receiving the stream leaving the capillary nozzle, and changing its cross section from circular to rectangular such that the stream exits from the further nozzle with a rectangular cross section, a device directing a laser beam normally to one flat side of the rectangular cross section at a location downstream of the further nozzle, and a radiation detector disposed for detecting radiation resulting from impingement of laser radiation on particles in the stream of rectangular cross section.

Apparatus for counting and classifying particles

Apparatus for counting and classifying particles and including a laser for producing a laser beam, a flow nozzle for hydrodynamically focussing a stream of such particles and directing the focussed stream to intersect the laser beam, a focussing system causing the laser beam to have a diameter which, at the point of intersection with the particle stream, is no greater than the width of the particles, and a detector disposed to receive the laser radiation transmitted by the particles as they pass through the laser beam.

Growing community of inventors

Hanover, Germany

Wolfgang G Eisert