The invention provides method for locating one or more substantially circular-shaped tissue sample positioned on a solid support. The method involves the steps of transmitting light of a preselected wavelength onto a tissue sample, wherein the light induces the tissue sample to autofluoresce, identifying the center location of the tissue sample using the autofluoresced light, correlating the coordinates of the center location of the tissue sample on the solid support using an x, y-coordinate system, and mapping the coordinates of the tissue sample on the solid support to differentiate tissue sample containing regions from blank regions on the solid support. In a second aspect, the invention provides an apparatus for locating one or more substantially circular-shaped tissue sample positioned on a solid support.