Abstract: A fluorescence detection scanner and method employing a fiberoptic collector, positioned adjacent to the scanning plane of the excitation beam, with a light collecting surface which is oriented to reject back-scattered excitation light from the incident surface of the sample support. The scanning plane of the excitation beam is off normal relative to the incident surface of the sample support and the light collecting surface is located within the area defined by the resulting acute angle of incidence. The light collecting surface is angled away from the location at which the incident excitation beam intersects the surface of the sample support so that back-scattered excitation light does not enter the optical fibers. The orientation of the light collector results in a four to five-fold decrease in excitation-light background without attenuation of the fluorescence emitted by the sample.