Patent ID: 7295306

Claim:
A fluorescent particle counter comprising: a microchip being comprised of a first inflow passage into which first liquid flows, a second inflow passage into which second liquid flows, a mixing portion connecting both said inflow passages, formed so as to be bent for mixing said first liquid said second liquid which flow therein, and an outflow passage located so as to connect with said mixing portion, through which said mixed liquid is drained; said microchip for mixing said first liquid including particles to be counted and said second liquid including fluorescent dyes in said mixing portion and for delivering fluorescent particles to said outflow passage; a fluorescent particle counting portion being comprised of a light source through which excitation light irradiates said fluorescent particles of said outflow passage, and a fluorescence measuring means for catching fluorescence which is generated due to irradiation of said excitation light onto said fluorescent particles so as to counter said delivered fluorescent particles; a sampling means for obtaining output of said fluorescence measuring means every constant time, and a counting means for counting a number of said fluorescent particles on the basis of said output of said sampling means; said fluorescent measuring means being a camera for obtaining stationary images in order every predetermined time; wherein said counting means counts a number of said fluorescent particles in a predetermined fluorescent distribution measurement area in each of said stationary images obtained by said fluorescence measuring means, and a width w of said predetermined fluorescent distribution measurement area in a direction where said fluorescent particles move meets the following expression width w of said predetermined fluorescent distribution measurement area is equal to moving speed of said fluorescent particles×time for said fluorescence measuring means from obtaining one said stationary image till obtaining the next image.