IBI’s Terrific Broth is used with Glycerol in cultivating recombinant strains of E.coli. Terrific broth is a highly enriched medium for improving yield in plasmid bearing E.coli. Recombinant strains have an extended growth phase in the medium. The addition of tryptone and yeast extract in the medium will allow higher plasmid yield per volume. Glycerol is used as a carbohydrate source in this formulation. Unlike glucose, glycerol is not fermented to acetic acid.