. "Methods in Yeast Genetics Cold Spring Harbor Laboratory, N.Y., 1981)) with plasmids of interest were grown at 30??? C. to A600 of approximately 5 in a medium of 2 percent galactose, 0.67 percent Yeast Nitrogen Base without amino acids (DIFCO), adenine (10 ??g/ml) and amino acids including methionine (Sherman, F. et al., supra)." . . .