High-Resolution Episcopic Microscopy (HREM) is a technique for visualising tissue samples, such as mouse embryos, as a large stack of successive 2D images. The resolution of the images approaches that of conventional histology and, since they are perfectly aligned, they can be used to construct very detailed 3D models. Contents: HREM technology overview Embryo harvesting HREM sample preparation Preparing blocks for imaging HREM embedding HREM imaging Using HREM data FAQ