Abstract: The present invention relates to a culture medium suitable for mammalian cell, tissue or embryo growth in vitro in which enhancers of oxidative phosphorylation are included. These enhancers include coenzyme Q, alpha.lipoic acid, acetyl-L-carnitine, alpha.tocopherol, These products are introduced into the medium in a soluble form through the use of either a polysorbate surfactant such as Tween ™ or a preparation containing lecithin and surfactant.