Combined whole-mount in situ hybridization and immunohistochemistry in avian embryos

The whole-mount In situ hybridization process has revolutionized the study of gene expression in the embryo. This procedure allows extremely sensitive detection of RNA transcripts and excellent spatial resolution. Numerous ex periments benefit from the detection of more than one marker molecule in th e same experimental embryo. While antisense RNA probes are extremely useful and methods for two-color in situ hybridization are available, antibodies recognizing specific protein species can help to expand the range of marker s detected. Here we present a protocol that permits the simultaneous locali zation of RNA transcripts and immunocytochemical localization of proteins i n the chick embryo. (C) 2001 Academic Press.