Apparatus and method for fluorescent detection in biological samples

A fluorometry device for determining concentration of spectrally distinguishable species in a biological sample is provided. The device comprises: a light source adapted to provide a source beam; a plurality of sample wells; a plurality of optical devices adapted to filter the source beam, to filter fluorescent light from the samples, and to separate the source beam from the fluorescent light, wherein each of the plurality of optical devices is coupled to a movable platform; and a detector adapted to receive the fluorescent light emitted from the samples, wherein the fluorescent light is not in focus and does not provide spatial content from a focus plane in the samples. The device provides a data signal representative of the concentration of spectrally distinguishable species based on the intensity of fluorescent light emitted by the samples.