Visualization of Fluorescent Protein Expression in Whole-Mount Postimplantation-Stage Mouse Embryos.

Fluorescent protein (FP)-expressing transgenic mice are powerful genetic resources for marking both live and fixed cells and tissues. Expression in live embryos requires only dissection and visualization using an appropriate microscope. Fixation can compromise FP activity. A simple tissue-clearing agent called Scae preserves FP activity while rendering the embryo or organ optically transparent.