Ultrastructural computerized quantitative morphometry of extracellular organelles in calcifying matrices

A recently developed method for image analysis at the ultrastructural level is described. The method comprises detection, classification, shape-analysis, and study of size and location of subcellular organelles on electron micrographs. Specifically, the method was used to analyze dimensions and distribution of extracellular matrix vesicles (MV), including their distance from the cell and from extracellular structures. This was performed in processes of normal and pathological calcification in primary bone and cartilage. Image analysis is carried out by hardware and software installed and operated in a PC-AT-type computer. Processing of data is performed automatically and followed by statistical analysis. Image analysis of ultrastructures in this biological process offers new aspects of understanding of formation and healing of calcified tissues. The study of these processes was based until now mainly on biochemical and qualitative ultrastructural observations. These presented morphometric methods can be used for the analysis of the distribution and behavior of different subcellular organelles in a wide range of biological processes.