Episcopic three-dimensional imaging of embryos

Episcopic fluorescence image capturing (EFIC) and high-resolution episcopic microscopy (HREM) are related techniques that are used to generate digital volume data and create three-dimensional (3D) images. Both techniques require specimens that are embedded in an appropriate medium, and images are captured from successive sections before removal from the embedded tissue block. EFIC detects autofluorescence emitted from the embedded tissue, whereas HREM requires the tissue to be stained with a fluorescent dye such as eosin. Different procedures are therefore necessary for embedding tissue for EFIC or HREM imaging. This article describes episcopic imaging and gives the advantages and disadvantages of the EFIC and HREM techniques. It also describes the imaging setup required to collect volume data and generate 3D images.