Automatic Analysis of TUNEL assay Microscopy Images

A computer method for the automatic analysis of specific fluorescence microscopy images, collected with a TUNEL assay procedure applied on human spermatozoa cells, has been developed in this work. In each image, the cells are shown in blue color while in the interior of every cell an area proportional to the degree of the cell DNA fragmentation has been stained in reddish color by the assay procedure. The proposed digital image analysis technique suggests a segmentation method based on the Primary Component Analysis (PCA) applied to the 3-D color space. In this way the shapes in every image are isolated and then a classification technique is used to obtain only the shapes representing solitary spermatozoa, to ignore those presenting cell overlapping and dispose small shapes-scraps belonging to fragments of useless material created during the assay procedure. Finally, for each solitary cell the ratio of the reddish area over the total cell area is estimated.