The method of rodent whole embryo culture using the rotator-type bottle culture system.

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology (1). Although development and growth of mammalian embryos are critically dependent on the function of the placenta, WEC technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages during embryonic day (E) 6.5-E12.5 in the mouse or E8.5-E14.5 in the rat (2, 3, 4). In WEC, we can directly target desired areas of embryos using fine glass capillaries because embryos can be manipulated under the microscope. Therefore, rodent WEC is very useful technique when we want to study dynamic developmental processes of postimplanted mammalian embryos. Up to date, several types of WEC systems have been developed (1). Among those, the rotator-type bottle culture system is most popular and suitable for long-term culture of embryos at midgestation, i.e., after E9.5 and E11.5 in the mouse and rat, respectively (1). In this video protocol, we demonstrate our standard procedures of rat WEC after E12.5 using a refined model of the original rotator system, which was designed by New and Cockroft (5, 6), and introduce various applications of WEC technique for studies in mammalian developmental biology.