Measurement by confocal laser scanning microscopy of the volume of epidermal nuclei in thick skin sections

The mean volume and shape of nuclei assessed in standard tissue sections by means of stereologic and morphometric methods are associated with prognosis in tumors of different sites. Thus, accurate quantification of the volume and shape of cell nuclei can be important for cancer patients and also may be useful for a better understanding of basic cellular events, such as growth and differentiation. Confocal laser scan microscopy (CLSM) makes it possible to obtain image sets consisting of very thin serial optical slices from thick tissue sections. These images can be used with digital image processing to construct a three-dimensional (3-D) model of individual nuclei. We used CLSM to study a 50-micron-thick paraffin section of a skin biopsy. Image processing was applied to the CLSM images to precisely segment epidermal nuclei from the background, and serial two-dimensional (2-D) binary images were created. Alignment of the 2-D images that form the 3-D model of the original nuclei was carefully controlled. The series of 2-D binary images was connected with an algorithm to form the 3-D model of each complete nucleus and organized for the 3-D visualization and analysis using a 3-D volume rendering method. In this way we measured the volume and surface area of 22 intact epidermal nuclei. The mean nuclear volume was 174.7 micron3, the standard deviation of the volume 26.47 micron3, the mean surface area 168.0 micron2 and the standard deviation of the surface area 22.00 micron2.(ABSTRACT TRUNCATED AT 250 WORDS)