How to Design Effective siRNA Molecules to Silence Specific Genes
A patent detailing the precise chemical structure and sequence requirements for siRNA molecules designed to effectively turn off the AAT gene in cells.
Original patent title: “Methods and compositions for selecting siRNA of improved functionality”
A patent detailing the precise chemical structure and sequence requirements for siRNA molecules designed to effectively turn off the AAT gene in cells. Granted to Thermo Fisher Scientific Inc in 2017 with 14 claims and 3 forward citations, and it is expected to expire in 2035.
Coverage
What does this patent actually cover?
This patent describes the structural requirements for small interfering RNA (siRNA) molecules used to trigger gene silencing. It specifies that the molecule must consist of a sense and antisense strand, each between 19 and 30 nucleotides long, forming a duplex region. Crucially, the antisense strand must be a complement to a specific target sequence identified as SEQ ID NO:465, which corresponds to the AAT gene. The patent allows for variations in the presence or absence of short nucleotide overhangs at the ends of the duplex.
The gap
What does this patent NOT cover?
- Does not cover siRNA molecules that target genes other than the AAT gene specified by SEQ ID NO:465.
- Does not cover RNA molecules longer than 30 nucleotides.
- Does not cover single-stranded RNA molecules.
- Does not cover methods of delivering these molecules into a living organism.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The innovation lies in the rational design criteria: by strictly defining the length (19-30 nucleotides) and the exact sequence complement required for the antisense strand, the inventors ensure the siRNA molecule is optimized for the cell's natural silencing machinery, minimizing off-target effects.
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
RNA interference research tools
Experimental gene silencing therapies for Alpha-1 Antitrypsin deficiency
Why it matters
The bigger picture
This patent is significant for the field of RNA interference (RNAi), a biological process where RNA molecules inhibit gene expression. By defining the exact sequence and structural parameters for targeting the AAT gene—often associated with Alpha-1 Antitrypsin deficiency—it provides a blueprint for developing therapeutic reagents that can precisely 'switch off' disease-causing genes.
Filed
November 9, 2015
Granted
December 12, 2017
Market context
Who's building on this
Companies in this space
Thermo Fisher Scientific remains a primary player in the development of RNAi reagents. Other biotech firms and academic labs working on gene therapy and RNA-based medicines continue to refine these structural design principles to improve the potency and stability of therapeutic siRNA.
Market impact
This patent contributes to the standardization of siRNA design, helping researchers move from trial-and-error discovery to predictable, rational design. It strengthens the intellectual property landscape for companies developing targeted genetic medicines by protecting specific, highly functional sequences for therapeutic use.
Claim 1 — Plain English
What this patent covers
This patent describes the structural requirements for small interfering RNA (siRNA) molecules used to trigger gene silencing. It specifies that the molecule must consist of a sense and antisense strand, each between 19 and 30 nucleotides long, forming a duplex region. Crucially, the antisense strand must be a complement to a specific target sequence identified as SEQ ID NO:465, which corresponds to the AAT gene. The patent allows for variations in the presence or absence of short nucleotide overhangs at the ends of the duplex.
The clever bit
The innovation lies in the rational design criteria: by strictly defining the length (19-30 nucleotides) and the exact sequence complement required for the antisense strand, the inventors ensure the siRNA molecule is optimized for the cell's natural silencing machinery, minimizing off-target effects.
What it does not cover
- Does not cover siRNA molecules that target genes other than the AAT gene specified by SEQ ID NO:465.
- Does not cover RNA molecules longer than 30 nucleotides.
- Does not cover single-stranded RNA molecules.
- Does not cover methods of delivering these molecules into a living organism.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
12/40
Early citations
Claim breadth
9/20
Moderate scope
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
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
$113K – $360K
Midpoint $225K · 9.3 yr remaining · 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
14 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Leake, D., Khvorova, A., Scaringe, S., Read, S., Marshall, W., & Reynolds, A. (2017). How to Design Effective siRNA Molecules to Silence Specific Genes (U.S. Patent No. 9,839,649). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/9839649/methods-and-compositions-for-selecting-sirna-of-improved-functionality
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 to Design Effective siRNA Molecules to Silence Specific Genes cover?
A patent detailing the precise chemical structure and sequence requirements for siRNA molecules designed to effectively turn off the AAT gene in cells.
Who owns patent US 9839649?
Thermo Fisher Scientific Inc owns this patent, granted in 2017.
When does this patent expire?
This patent is expected to expire on November 9, 2035, when the invention enters the public domain.
What is patent US 9839649 cited by?
This patent has been cited by 3 later patents that build on its ideas.
What problem does this patent solve?
This patent is significant for the field of RNA interference (RNAi), a biological process where RNA molecules inhibit gene expression. By defining the exact sequence and structural parameters for targeting the AAT gene—often associated with Alpha-1 Antitrypsin deficiency—it provides a blueprint for developing therapeutic reagents that can precisely 'switch off' disease-causing genes.
What does this patent NOT cover?
Does not cover siRNA molecules that target genes other than the AAT gene specified by SEQ ID NO:465.
Patent monitoring