Recombinant DNA technology has revolutionized the production of insulin, making it more efficient and scalable. This biotechnology involves the insertion of the human insulin gene into bacterial DNA, enabling bacteria to produce insulin identical to that naturally produced by the human body.

Here’s how it works:

1. **Gene Isolation**: The human insulin gene is isolated using restriction enzymes, which cut DNA at specific sequences.
2. **Plasmid Insertion**: The isolated insulin gene is inserted into a plasmid (a small circular DNA molecule) using DNA ligase, which seals the gene into the plasmid. Plasmids serve as vectors to transfer genetic material.
3. **Transformation**: The recombinant plasmid is introduced into Escherichia coli (E. coli) bacteria. This process, called transformation, allows the bacteria to take up the plasmid and incorporate it into their own DNA.
4. **Cultivation**: The genetically modified bacteria are cultivated in large fermentation tanks. As the bacteria grow and divide, they express the insulin gene, producing human insulin.
5. **Extraction and Purification**: The insulin is then harvested from the bacterial cultures and purified to ensure it is free from contaminants and suitable for medical use.

This method, pioneered in the 1980s, replaced the previous reliance on animal-derived insulin, which was less efficient and posed higher risks of allergic reactions. Recombinant DNA technology has thus enabled the mass production of high-quality, human-compatible insulin, significantly benefiting people with diabetes worldwide.