A data processing apparatus comprising: a data determination portion configured to specify, in each of first light intensity distribution data and second light intensity distribution data representing a distribution of light intensity with respect to time or position, an analysis range comprising a temporal or spatial interval corresponding to a storage area (W1, W2, W3) for storing a detection target, the first light intensity distribution data being acquired on the basis of light emitted from a first light source to a detection area, the second light intensity distribution data being acquired on the basis of light emitted from a second light source to the detection area where the second light source is temporally or spatially offset from the first light source; and a mode selection portion configured to select an operation mode of the data determination portion, wherein the mode selection portion is configured to select one of a first mode in which the data determination portion is configured to specify the analysis range in each of the first light intensity distribution data and the second light intensity distribution data, wherein in the first mode, the data determination portion is configured to specify the analysis range (R21, R22, R23) of the second light intensity distribution data without using information on the analysis range (R11, R12, R13) of the first light intensity distribution data, and a second mode in which the data determination portion is configured to specify the analysis range (R21, R22, R23) in the second light intensity distribution data on the basis of information on the analysis range (R11, R12, R13) of the first light intensity distribution data. a data determination portion configured to specify, in each of first light intensity distribution data and second light intensity distribution data representing a distribution of light intensity with respect to time or position, an analysis range comprising a temporal or spatial interval corresponding to a storage area (W1, W2, W3) for storing a detection target, the first light intensity distribution data being acquired on the basis of light emitted from a first light source to a detection area, the second light intensity distribution data being acquired on the basis of light emitted from a second light source to the detection area where the second light source is temporally or spatially offset from the first light source; and a mode selection portion configured to select an operation mode of the data determination portion, wherein the mode selection portion is configured to select one of a first mode in which the data determination portion is configured to specify the analysis range in each of the first light intensity distribution data and the second light intensity distribution data, wherein in the first mode, the data determination portion is configured to specify the analysis range (R21, R22, R23) of the second light intensity distribution data without using information on the analysis range (R11, R12, R13) of the first light intensity distribution data, and a second mode in which the data determination portion is configured to specify the analysis range (R21, R22, R23) in the second light intensity distribution data on the basis of information on the analysis range (R11, R12, R13) of the first light intensity distribution data.