Preparation of Rat Serum for Culturing Mouse Embryos: Figure 1.

INTRODUCTION The most important component of proper mammalian embryo culture is high-quality rat serum. Some commercial sources exist, but control over anesthetization methods and serum extractions means that preparations consistently give superior results. To obtain ∼100 mL of rat serum, 30 adult male Sprague Dawley rats must be used. Depending on the number of cultures performed per week, this amount of rat serum can last for several months. This protocol requires two people to collect blood from the rat.