Patent ID: 8049185

Claim:
A fluorescence detection device for measuring fluorescence emitted from a measurement object flowing through a flow channel by irradiation with a laser light, comprising: a laser light source unit that irradiates, with a laser beam, a measurement object passing through a measurement point in a flow channel; a first light-receiving unit comprising an optical system that collects forward-scattered laser light from the measurement object and a plurality of detectors arranged side by side in a direction perpendicular to a direction of an optical axis of the laser beam and to a direction in which the measurement object flows through the flow channel in order to receive the collected forward-scattered light to inform the timing of passage of the measurement object through the measurement point and to detect a focus position of the collected forward-scattered light; a second light-receiving unit that receives, through a collecting lens, fluorescence emitted from the measurement object irradiated with the laser beam and outputs a light-reception signal; and a processing unit that uses one of detection signals outputted from the first light-receiving unit as a trigger signal to start data processing performed based on the light-reception signal outputted from the second light-receiving unit and the detection signals, and outputs an output value of fluorescence intensity, wherein the processing unit identifies a focus position of the forward-scattered light by finding a signal of a highest output level among the detection signals outputted from the first light-receiving unit and determines, based on the thus determined focus position, a correction factor for correcting the light-reception signal outputted from the second light-receiving unit, and corrects the light-reception signal using the correction factor.