Three-dimensional reconstruction: a tissue embedding method for alignment of serial sections

Three-dimensional (3D) reconstruction from serial sections that are undistorted and true-to-life is only possible when a reference system exists that allows correct matching of the section drawings. This paper describes a simple method for producing reference lines that ensures proper alignment of the drawings. (1) The specimen is embedded in a rectangular form, (2) the sides of the block are painted, and (3) the embedded specimen is sectioned exactly perpendicular to the painted sides of the block. Thus, in each section the paint appears as dark lines which serve as reference lines for matching the sections.