This video demonstrates the protocol for isolating and culturing explants of the mouse forebrain from embyonic day 12 mice. Procedures for removal of the uterus, embryos from uterus, and dissection of embryos are given. In addition the methodology for transferring these explants onto specialized membranes on which they are cultured is demonstrated. The development of the forebrain can be studied in vitro using this preparations as well as changes in gene expression.