JPH029309B

PURPOSE:To enable the quantitative and rapid measurement of chromosomes or cells, by applying a laser beam being thinner than the diameter of the chromosomes or the cells and by detecting the intensity of light emitted therefrom. CONSTITUTION:A sheath liquid 7 is sent into a flow chamber 6 by a pressurizing device 8, while a sample liquid 5 wherein chromosomes or cells are in suspension is sent into the chamber 6. Next, fine vibrations are applied to the inside of the chamber 6 by means of a piezoelectric vibrator 9, and thereby a droplet containing he cells 4 is made to drop. Then, laser beams 1A and 1B restricted to be thinner than the diameters of the cells are applied to the cells 4, and fluorescence emitted from fluorescent matter in the cells 4 is detected by photomultiplier tubes 18A-18D through the intermediary of lenses 16A, 16B and dichroic filters 17A, 17B. Then, detection signals from the tubes 18A-18D are analyzed by using a high-speed profile pattern processing device 19, CPU 20, etc., and a signal as to whether the cells 4 are to be extracted or not is outputted from CPU 20. When the signal from CPU 20 is an extraction signal, an electric charge is impressed 11 on the droplet 10, and the droplet 10 is gathered selectively in a water droplet catching unit 13 through between deflecting plates 12.