ABSTRACT
To facilitate a quantitative morphological analysis of early mouse development under controlled conditions, a perfusion culture system capable of supporting embryogenesis to blastocyst stage has been developed. The use of a mesh system allows identification of individual embryos by position, and control of their orientation during culture and preparation for light and electron microscopy. Quantitative evaluation of tissue-processing procedures has permitted selection of conditions which reduce changes in linear dimensions to –1·6 ± 1·8% in two-cell embryos. Through the definition of a coordinate system based on mesh structure and the development of a special sectioning procedure, sections can be localized within the intact embryo and three-dimensional coordinates given to any element of embryo volume.
