A system (1) for collecting biological information on a dyed biological particle (cell or chromosome) by irradiating light onto liquid containing the dyed biological particles and for detecting information light therefrom is provided according to the present invention. The system includes a path-defining structure (2) of transparent material defining a flow path (3) through which the liquid containing the dyed biological particles runs, an irradiation apparatus (5) for irradiating light onto the particles passing through the flow path (3), a first detecting apparatus (21) for detecting first information light obtained from the irradiated particle, and a second detecting apparatus (25) for detecting second information light obtained from the irradiated particle. At least one of the first and second detecting apparatuses (21, 25) includes one or more fiber optics (26, 27), of which one ends (61, 62) are arranged adjacent the flow path (3) so as to collect the information light.