Two features typifying normal breast tissue were identified: adipose tissue and the presence of collagen fibres in the stroma. As shown in Figs. 2(a) and 2(b), the fluorescence images obtained from methylene-blue and acriflavine-stained adipose tissue are similar: the well-defined and uniform nonfluorescent polygon shape of the adipose tissue with hyperfluorescent borders can clearly be observed in both cases. Nuclei, which may not always be clearly visible, appear as sparsely populated bright spots on the borders. In Figs. 2(d) and 2(e), the fibrous connective tissue appears as hyperfluorescent bundles of elastic wavy fibres. Figures 2(g) and 2(h) represent fibrocystic changes, where compressed bright slit-like glandular spaces are surrounded by loose fibrous stroma. In Figs. 2(j) and 2(k), stroma composed of hyperfluoroscent spindle-shaped fibroblasts appear surrounded by gray collagen fibers. Also, both the systems enable visualization of distinctive neoplastic changes characterized by increased cellularity in the stroma, as depicted in Figs. 2(m) and 2(n). The disorganized distribution of cell nuclei and the unclear tissue architecture was clearly visible as large clusters of hyperfluorescent spots. Similar features are observed in matched histology images of acriflavine-stained tissue (c, f, i, l, and o). Furthermore, we compared the signal-to-noise ratio (SNR) of the two sets of images, obtained by the ratio of the mean intensity of a homogenous stained area of of the tissue (signal) to the standard deviation of an unstained region of (noise). Averaged across 100 images, the SNR was () for the acriflavine-stained images and () for the methylene-blue stained images. Therefore, despite the differences in stain, imaging system and processing, the noise in the final processed images are broadly comparable.