Whole-Mount In Situ Hybridization of Mouse Embryos Using DIG-Labeled RNA Probes

Whole-mount in situ hybridization (WMISH) is a commonly used technique for visualizing the expression profile of mRNAs in embryos. Unlike traditional in situ hybridization techniques, which require thin tissue sections, the WMISH technique allows gene expression patterns to be assessed over the entire embryo and structure. Here, we describe the detailed procedural steps of WMISH, including probe production, embryo fixation and staining, and post-hybridization signal detection. Using this protocol, we visualized highly specific expression patterns of Sonic hedgehog and Bmp4 mRNAs in E12.5 mouse embryos.