Time-resolved DNA-microarray reading by an intensified CCD for ultimate sensitivity

We describe a novel technique for DNA-microarray reading based on time-reso lved fluorescence measurements. We used an intensified CCD camera with pico second resolution to acquire a set of time-delayed fluorescence images from a mutation DNA microarray marked with cyanine 3. We measured the fluoresce nce lifetimes of the marker and the background separately, and we used this information to calculate the amplitude map of the marker, starting from th e time-delayed images. This procedure allowed us to identify hybridized spo ts that are not visible in fluorescence images acquired with continuous-wav e detection. (C) 2000 Optical Society of America OCIS codes: 170.6920, 170. 0110, 260.2510, 170.3880.