You can freely build on How Scientists Taught Bacteria to Make Human Hormones

What this patent covers

This patent describes a method for inserting synthetic DNA into a bacterial plasmid—a small, circular piece of DNA—so the bacteria acts like a factory. The key innovation is using 'codon optimization,' where the synthetic gene is written using the specific DNA 'language' that bacteria prefer, making them much more efficient at reading the instructions to build human proteins. By placing this gene between specific DNA 'cut sites' (restriction endonuclease sites), researchers could reliably insert and express mammalian hormones like somatostatin or insulin chains within a microbial host.

What is now free to use

All 1 claims of US 4356270 are in the public domain. Specifically:

The 1 dependent claim add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover naturally occurring DNA sequences that have not been synthetically modified for microbial expression.

• Does not cover the use of non-bacterial hosts like yeast or mammalian cell cultures for protein production.

• Does not cover the specific medical treatments or clinical applications of the hormones produced.

• Does not cover gene editing techniques like CRISPR that modify DNA in place rather than using cloning vehicles.

Who is building on this today

Genentech, now a member of the Roche Group, remains a major player in this space. Virtually every modern pharmaceutical company, including Eli Lilly and Novo Nordisk, relies on the foundational principles of recombinant DNA technology established by this patent.

Products built on expired version of this technology

How to cite this patent in your documentation

Genentech Inc. US Patent 4356270. Recombinant DNA cloning vehicle. Granted 1982, expired 1999. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.