How Scientists Taught Bacteria to Make Human Hormones
Genentech's 1979 patent on using engineered DNA to force bacteria to produce human proteins like insulin and growth hormones.
Original patent title: “Recombinant DNA cloning vehicle”
Genentech's 1979 patent on using engineered DNA to force bacteria to produce human proteins like insulin and growth hormones. Granted to Genentech Inc in 1982 with 10 claims and 86 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
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.
The gap
What does this patent NOT cover?
- 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The inventors realized that bacteria have a 'preference' for certain DNA codes; by rewriting the synthetic gene to use these preferred codons, they drastically increased the amount of human protein the bacteria could produce.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Synthetic human insulin (Humulin)
Human growth hormone production
Recombinant protein manufacturing platforms
Why it matters
The bigger picture
This patent is a cornerstone of the modern biotechnology industry. It provided the legal and technical framework for producing life-saving human proteins, such as synthetic insulin, which replaced the previous, less-effective method of harvesting insulin from the pancreases of slaughtered cows and pigs.
Filed
November 5, 1979
Granted
October 26, 1982
Market context
Who's building on this
Companies in this space
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.
Market impact
This patent effectively launched the commercial biotechnology industry. It enabled the transition from animal-derived medicine to laboratory-grown medicine, creating a multi-billion dollar market for recombinant therapeutics and setting the standard for how biological drugs are manufactured today.
Claim 1 — Plain English
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.
The clever bit
The inventors realized that bacteria have a 'preference' for certain DNA codes; by rewriting the synthetic gene to use these preferred codons, they drastically increased the amount of human protein the bacteria could produce.
What it does not cover
- 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.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Strong
Citation count
39/40
Highly cited
Claim breadth
7/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
20/20
Major company or institution
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$68K – $216K
Midpoint $135K · expired or expiring · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Patent Claims
0 independent claims · 1 dependent
Claims are the legal boundaries of the patent. An independent claim stands alone. A dependent claim adds limitations to its parent, narrowing — but not broadening — the scope.
The original legal language
Original claims
10 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Itakura, K. (1982). How Scientists Taught Bacteria to Make Human Hormones (U.S. Patent No. 4,356,270). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/4356270/recombinant-dna-cloning-genentech
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Scientists Taught Bacteria to Make Human Hormones cover?
Genentech's 1979 patent on using engineered DNA to force bacteria to produce human proteins like insulin and growth hormones.
Who owns patent US 4356270?
Genentech Inc owns this patent, granted in 1982.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 4356270 cited by?
This patent has been cited by 86 later patents that build on its ideas.
What problem does this patent solve?
This patent is a cornerstone of the modern biotechnology industry. It provided the legal and technical framework for producing life-saving human proteins, such as synthetic insulin, which replaced the previous, less-effective method of harvesting insulin from the pancreases of slaughtered cows and pigs.
What does this patent NOT cover?
Does not cover naturally occurring DNA sequences that have not been synthetically modified for microbial expression.
Same assignee
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