Here's how it works:
1. Isolation of the human insulin gene: The gene coding for human insulin is isolated from human cells.
2. Insertion into a bacterial plasmid: The insulin gene is inserted into a bacterial plasmid, a small circular DNA molecule. This plasmid acts as a vector, carrying the gene into the bacteria.
3. Transformation of bacteria: The modified plasmid is introduced into bacteria, which take it up and incorporate it into their own DNA.
4. Production of insulin: The bacteria now contain the human insulin gene and can produce human insulin as a protein.
This process is called genetic engineering, where the genetic makeup of an organism is altered to produce a desired product.
