Stanley Cohen and Herbert Boyer inserted the recombinant DNA molecule they created into E. coli bacteria by means of a plasmid, thereby inducing the uptake and expression of a foreign DNA sequence known as "transformation."
DNA transformation is a naturally occuring but rare event in which DNA can be transferred into bacteria. In 1970, Morton Mandel and Akiko Higa discovered a way to make E. coli more "competent" for transforming foreign DNA. Their calcium chloride method is
Professor Douglas Hanahan explains that a fundamental property of multi-cellular organisms is the capability to have cells commit suicide or undergo apoptosis, which is a form of programmed cell death.