Linear DNA Assembly from RCA Concatemers for Faithful Long Sequences

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods struggle to completely and faithfully amplify large and complex DNA products, such as those with sequences greater than 15kb, GC-rich regions, or regions with repeated sequences, making it difficult to produce stable DNA products suitable for research and therapeutic applications.

Innovation Solution

A method involving rolling circle amplification of DNA templates to generate concatemers, followed by forming a single contiguous aqueous volume with endonucleases and ligases to digest and ligate the concatemers, resulting in linear DNA products with closed or open ends, suitable for therapeutic and research applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional amplification methods are used to amplify large and complex DNA products, then amplification can be performed, but the amplification is incomplete and unfaithful

Engineering Contradiction:
Improveamplification fidelityVSAvoidamplification completeness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the amplification process into two distinct stages: first, rolling circle amplification to generate concatemeric DNA products, and second, enzymatic digestion with endonucleases to cleave the concatemers into individual linear DNA molecules. This segmentation allows each stage to optimize for its specific function, achieving both high fidelity and completeness in the final amplified product

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs preliminary action by performing rolling circle amplification first to generate concatemeric intermediaries before the final cleavage step. This preliminary amplification stage creates a reservoir of DNA that can then be precisely processed by endonucleases, ensuring that the final linear DNA products are complete and faithful representations of the original template

Inventive Principle:
Principle #10Preliminary action

2Productivity

If rolling circle amplification is used to generate concatemers, then amplification efficiency is improved, but the DNA products are in a concatemeric form that requires further processing

Engineering Contradiction:
Improveamplification efficiencyVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into a single reaction vessel by combining the rolling circle amplification reaction with subsequent endonuclease digestion and ligase treatment. This allows the concatemeric intermediaries to be generated and processed in one continuous workflow, transforming the intermediate concatemeric form into final linear DNA products without requiring separate purification and processing steps

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The concatemeric DNA products serve as intermediaries in the overall process. They are generated by rolling circle amplification and then serve as substrates for endonuclease cleavage. This intermediary form allows the system to achieve high amplification efficiency while providing a defined intermediate state that can be precisely processed to generate the final linear DNA products

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If endonucleases and ligases are used in a single reaction volume, then linear DNA products are produced efficiently, but the reaction conditions must be optimized for multiple enzymes

Engineering Contradiction:
Improvelinear DNA production efficiencyVSAvoidreaction condition optimization
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a single reaction volume that supports multiple enzymatic functions: rolling circle amplification, endonuclease digestion, and ligase-mediated joining. By selecting enzymes and conditions that are compatible across all three functions, the system achieves efficient linear DNA production in one pot, eliminating the need for separate optimization of multiple reaction conditions

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method enables the production of stable linear DNA products that faithfully represent the original templates, overcoming the challenges of amplifying complex sequences, suitable for research and therapeutic applications.

Implementation Method 1

forming a single contiguous aqueous volume comprising a first amplified DNA product, a second amplified DNA product, an endonuclease and a ligase

Methodology Applied
Scientific EffectEndonuclease digestion: Enzyme

Implementation Method 2

forming a single contiguous aqueous volume comprising a first amplified DNA product, a second amplified DNA product, an endonuclease and a ligase

Methodology Applied
Scientific EffectDNA ligation: Enzyme

Implementation Method 3

the first amplified DNA product and/or the second amplified DNA product is/are product(s) of rolling circle amplification (RCA)

Methodology Applied
Scientific EffectRolling circle amplification:

Data Source

PatentEP4686761A1Linear DNA products produced from multiple amplified DNA products
Publication Date: 2026.02.04 4BASEBIO UK LTD
  • EP4686761A1 patent drawingFigure 1
  • EP4686761A1 patent drawingFigure 2A
  • EP4686761A1 patent drawingFigure 2B

AI summary

The invention provides methods for producing a linear deoxyribonucleic acid (DNA) product comprising a linear portion of each of at least two amplified DNA products (e.g. a linear portion of a first amplified DNA product and a linear portion of a second amplified DNA product). The invention also provides linear DNA products comprising a linear portion of each of at least two amplified DNA products and uses thereof.