There is provided a data processing apparatus including: a data determination portion that specifies, in each of first and second light intensity distribution data, an analysis range corresponding to a storage area for storing a detection target, the first and second light intensity distribution data being acquired on the basis of light emitted from first and light sources to a detection area; and a mode selection portion that selects an operation mode of the data determination portion. The mode selection portion selects one of a first mode in which the data determination portion specifies the analysis range in each of the first light intensity distribution data and the second light intensity distribution data, and a second mode in which the data determination portion specifies the analysis range in the second light intensity distribution data on the basis of information on the analysis range of the first light intensity distribution data.