| abstract |
Provided is an ex vivo medium for causing normal progress to the blastocyst stage without stopping development in the ex vivo culture of fertilized eggs. The normal development rate of fertilized eggs is improved by using 5-aminolevulinic acids shown by formula (I) (in the formula, R 1 represents a hydrogen atom or acyl group, R 2 represents a hydrogen atom, linear or branched alkyl group, cycloalkyl group, aryl group, or aralkyl group) or salts thereof as an agent for improving the normal development rate of fertilized eggs. |