Whole-mount fluorescence immunocytochemistry on Xenopus embryos

INTRODUCTIONImmunocytochemistry (ICC) is widely exploited in studying mammalian systems, but is underutilized among Xenopus developmental biologists. This stems, in part, from the relatively small number of Xenopus antibodies available for use in research. Common misconceptions about ICC in Xenopus embryos also prevail, discouraging researchers from trying the procedure. However, ICC with Xenopus is simple and effective. This article describes methods for whole-mount ICC in Xenopus embryos. Also included are simple procedures to quench autofluorescence of Xenopus and to remove surface pigment from embryos which may interfere with fluorescence imaging. The methods described here are useful for detecting tissue-specific probes (e.g., 12/101 to detect somites). They are also effective for imaging the cytoskeleton (e.g., α-tubulin to detect microtubules) or localizing specific proteins at the subcellular level (e.g., ZO-1 to detect tight junctions). In addition, combining ICC with in situ hybridization is simple and highly effective.