Over many years the FDA had had prodigious experience with insulins and with drugs derived from various microorganisms, so it was decided that no fundamentally new regulatory paradigms were necessary to evaluate the recombinant human insulin.

FORBES: When Genetic Engineering Came Of Age

After obtaining from Genentech, Inc. the recombinant E. coli bacteria that contained the genetic blueprint for and that synthesized human insulin, they developed processes for the large-scale cultivation of the organism (in huge fermenters similar to those that make wine or beer) and for the purification and formulation of the insulin.

FORBES: When Genetic Engineering Came Of Age