Successful whole embryo culture with commercially available reagents

Since its development in the 1970's, whole embryo culture (WEC) has provided an important method of growing and observing murine embryos ex utero. During WEC, embryos are immersed in a combination of rat serum and cell culture media, and supplied with heat and appropriate mixtures of CO₂ and oxygen that mimic growth conditions in utero. One significant factor limiting the widespread use of WEC is the perception that commercially produced rat serum is inadequate to support normal rates of embryonic growth and development. Conversely, production of serum 'in-house' is technically demanding, time-consuming and expensive. The current study aimed to identify a WEC medium comprising commercially manufactured rat serum that would produce cultured embryos of comparable standard to those grown in utero. A mixed culture medium, composed of 50% commercial rat serum and 50% F12 Ham's cell culture medium with an N-2 neuronal cell growth supplement, was shown to support both a rate of growth, and the development of a range of features comparable to that which normally occur in vivo. Furthermore, the F12 (N-2) supplemented rat serum displayed a very low propensity to induce morphological abnormalities during the culture period. The study establishes a novel method of successful WEC using readily available commercial reagents and should enable the broader use of WEC.