A multi-modal data acquisition system for detecting target material on a biological reaction surface, the system comprising a radiation source for generating an incoming beam that impinges on the biological reaction surface at an oblique incidence angle and produces a reflected beam, an interferometric detector for detecting an interferometric signal from the illuminated surface, the reflected beam being directed to the interferometric detector, a fluorescence detector for detecting a fluorescence signal from the illuminated surface; the fluorescence detector being positioned to substantially minimize the incidence of the reflected beam; and a processing system for receiving the interferometric and fluorescence signals and determining the presence or absence of target material on the biological reaction surface. A reaction surface conditioned for the simultaneous collection of fluorescence, interferometric and other signals. A multi-modal data acquisition system for collecting and processing additional modes, including multiple interferometric, fluorescence and scattering channels.