Histological sectioning was one of the first methods of analyzing embryonic development and has always been the gold standard for phenotypic analysis. In addition to being invasive and time consuming, a large sample size is often required at each developmental stage. Moreover, the process of fixing the embryo can significantly alter its gross morphology and appearance.7,8 Noninvasive imaging techniques would overcome these limitations and could potentially enable live imaging. Several noninvasive imaging techniques, such as confocal microscopy, ultrasound biomicroscopy (UBM), micro-magnetic resonance imaging (MRI), and micro-computed tomography (CT), have been employed to study embryonic development.9 Despite its high resolution, confocal microscopy is limited for embryonic imaging, especially at later stages of development, because of its insufficient imaging depth and requirement of fluorescent markers.10–12 With a penetration depth of few centimeters, UBM is a powerful embryonic imaging technique, but its limited spatial resolution of 30 to makes it unsuitable for imaging fine structures and processes, e.g., embryonic cardiovascular investigations in small animals.13,14 Micro-MRI can also achieve similar high spatial resolutions of 25 to .15–17 However, long acquisition times restrict the use of micro-MRI for live embryonic imaging. Although micro-CT offers a high spatial resolution of 2 to , the use of external contrast agents that may be toxic for embryos and potentially hazardous ionizing radiation makes micro-CT undesirable for imaging live embryos.18–20 Optical projection tomography (OPT) is a relatively new technique for three-dimensional (3-D) imaging of embryos with very high spatial resolutions (1 to ). However, the need for tissue fixation and optical clearing makes it unfeasible for live embryonic imaging.7,8,21 Selective plane illumination microscopy (SPIM) is a technique capable of providing multidimensional, high resolution images of embryos. Although a number of studies have been performed on zebrafish and medaka fish embryos,22,23 live murine embryonic imaging using SPIM is difficult as embedding the embryo in agarose is necessary to prevent motion of the sample.