Whole-mount in situ hybridization (WISH) is a reliable and specific method to study three-dimensional patterns of gene expression. A labeled nucleic acid probe anneals to a complementary target sequence and is visualized and localized in the embryo. This chapter describes a sensitive method for WISH on mouse embryos using digoxigenin-labeled RNA probes. The technique can be used for the analysis of gene expression patterns during early stages of odontogenesis and in tooth explants.
