The first product developed by genetic engineering was human insulin. It can be produced by using recombinant DNA technology. The gene responsible for producing human insulin protein is isolated from a human cell. A plasmid is isolated from a bacterial cell. Special restriction enzymes are used to cut the plasmid. The gene for insulin is inserted into the plasmid. This process is called recombination. The bacterial DNA now contains the human insulin gene and is inserted into a bacteria. the insulin gene translates and produces the recombinant insulin.