Labeling embryonic cells to trace their motion is a classical experimental approach with a host of techniques being used to mark live cells and tissues. Genetically engineered fluorescent protein vectors (DNA plasmids) are a recent technology well suited to time-resolved studies of cellular motion in live embryos. DNA plasmids encoding fluorescent proteins can be introduced into cells using several methods, including electroporation, a technique used widely for analysis of tissue culture and embryonic cells. Here we describe a technique designed to introduce DNA plasmids into early gastrulation stage quail embryos, ex ovo. The method is effective, and with practice enables an investigator to direct the vectors to relatively confined regions of gastrulating embryos. The required electroporation chamber can be fabricated from common laboratory materials. We anticipate that using this method of labeling cells in a warm-blooded embryo, during gastrulation, will be a fruitful means of studying subsequent embryogenesis.