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How can genetic engineering produce human insulin and other useful medicines?

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CRISPR-Cas9; gene editing — gene editing The CRISPR-Cas9 gene-editing complex from the bacterium *Streptococcus pyogenes*.

Genetic engineering produces human insulin and other vital medicines primarily through recombinant DNA technology, which allows scientists to transform microorganisms into biological "factories" for protein synthesis.12

The process generally involves these steps:
* Gene Identification: Scientists identify the specific DNA sequence that codes for a desired human protein, such as insulin or growth hormone.3
* Insertion: This genetic material is inserted into the DNA of a host organism, commonly bacteria like Escherichia coli or yeast.243
* Synthesis: The host organism reads the inserted human gene and produces the corresponding protein as part of its normal cellular activity.23
* Scale-up: These engineered organisms are grown in controlled laboratory cultures, allowing for the large-scale, scalable production of pure, safe human proteins.24

This method has revolutionized medicine by replacing older, less efficient extraction techniques from animal tissues. Beyond insulin, this technology is used to manufacture vaccines, blood-clotting factors, and various therapeutics for conditions like cancer and viral infections.214