E. coli is a very common model organism for molecular biology and a really popular tool for generating synthetic proteins. (Yeast too). Bacteria have a neat fe

E. coli is a very common model organism for molecular biology and a really popular tool for generating synthetic proteins. (Yeast too). Bacteria have a neat feature where, in addition to their "main" chromosomal DNA, they also have small circular "loops" of DNA called plasmids that can be copied independently. In 1973, Cohen and Boyer demonstrated that one could "cut" a piece of DNA from one source, insert it into an E. coli plasmid, and then coax the cells into producing the protein coded for by the edited gene. This trick lets you generate "heterologous proteins" by purifying them from the cells or can change how the cell behaves. E coli. can't make every kind of proteins, but they can make a lot of them. It's also cheap and easy to grow, so it's often the "default" approach.