Requirements for Glucose and Amino Acids in Defined Media for Chick Embryos

Abstract

Experiments were conducted to determine the response of young chick embryos to amino acids and glucose in a defined medium for yolk-sac perfusion. As the concentration of glucose in the medium was increased from zero to 5.0 g/liter, the median survival of the embryos increased from 24 to 80 hours of perfusion. A similar increase in survival was obtained when amino acids in a medium containing 1.5 g of glucose/liter were increased from 0 to 4.8 g/liter. It is proposed that these effects may be attributable, in part, to changes in the total solute concentration of the medium. It has been shown, however, that glucose also exerts an effect on survival which is independent of solute concentration. When lysine or valine was omitted from the defined medium, there was a marked reduction in survival: the omission of lysine produced a smaller effect than the omission of valine. When these amino acids were omitted from the medium supplemented with 2.5 ml of yolk and 5 ml of egg white/liter, survival was not decreased, thus indicating the relative effectiveness of small amounts of yolk and egg white as sources of amino acids for the embryo.