[A method of the mesa trimming with glass knives for the obtaining the large series of ultrathin sections].

Ultrastructural analysis of tissue based on 3D reconstruction from serial ultrathin sections is one of the most adequate methods in the research of spatial organization of biological objects. Sample preparation technique for 3D reconstruction includes two technically the most difficult procedures: an obtaining of a stable ribbon of serial sections and the mounting of the ribbon onto a grid coated with support film. Both special approaches and technical tools for mounting of the ribbon onto the film have been proposed and well appreciated. Much attention has been paid to obtaining the large and stable ribbon of serial section but this mainly concerned the selection of epoxy embedding media. The critical condition for the obtaining the straight and stable ribbon is the precise parallelism of leading (bottom) and trailing (top) edges of the mesa falling onto the cutting edge. The trimming of mesa with dry diamond knife for cryoultratomy allows fulfilling this rule. In the given report, a method for obtaining parallel edges of mesa by means of two forms of glass knives is offered.