Phenotyping transgenic embryos: a rapid 3-D screening method based on episcopic fluorescence image capturing

We describe a technique suitable for routine three-dimensional (3-D) analysis of mouse embryos that is based on episcopic fluorescence images captured during serial sectioning of wax-embedded specimens. We have used this procedure to describe the cardiac phenotype and associated blood vessels of trisomic 16 (Ts16) and Cited2-null mutant mice, as well as the expression pattern of an Myf5 enhancer/beta-galactosidase transgene. The consistency of the images and their precise alignment are ideally suited for 3-D analysis using video animations, virtual resectioning or commercial 3-D reconstruction software packages. Episcopic fluorescence image capturing (EFIC) provides a simple and powerful tool for analyzing embryo and organ morphology in normal and transgenic embryos.