The epiphyseal growth plate and articular cartilage matrices were preserved by slam freezing and freeze substitution to optimally retain the native organization for both cellular and matrix components. These specimens were stained and examined using conventional electron microscopic methods. The highly integrated, proteoglycan-rich matrices were examined by computer image analysis using such parameters as distribution, connectivity, orientation, and a variety of morphometric analyses. Also, different aspects of electron tomography and 3D rendering of matrix vesicles and their associated mineral deposits from epiphyseal growth plates and turkey leg tendons are presented.