Wholemount In Situ Hybridization of Xenopus and Zebrafish Embryos

Wholemount in situ hybridization (WISH) is a technique widely used to study the expression patterns of developmentally regulated genes. The last few years have seen massive improvements in the protocol. Not only can we now detect weak signals much more clearly but we can also visualize two, or even three, mRNAs in the same embryo. This allows a finer dissection of the spatial and temporal relationships between the expression of genes, even to the level of being able to show simultaneous expression of two genes within one cell.