Surface-Bound Transposome Complexes for PCR-Free DNA Libraries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nucleic acid library preparation methods for next-generation sequencing are inefficient, costly, and introduce bias due to PCR amplification, particularly in GC-rich regions, leading to gaps and reduced indel calling performance.
Innovation Solution
A transposome complex immobilized on a solid support is used to fragment and tag nucleic acids without PCR amplification, incorporating index sequences through tagmentation, extension, and ligation, reducing bias and improving indel calling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If PCR amplification is used to generate nucleic acid libraries, then library yield is increased, but bias is introduced particularly in GC-rich regions leading to gaps and reduced indel calling performance
Solution Approach 1:
The invention extracts and eliminates the PCR amplification step from the library preparation workflow. By using transposome-mediated tagmentation followed by direct sequencing library construction, the method removes the source of GC-rich region bias and indel calling errors while maintaining sufficient library yield through efficient transposase-mediated fragmentation and tagging.
Solution Approach 2:
The invention replaces the biochemical PCR amplification mechanism with a transposase-based mechanical insertion mechanism. The transposome complex directly inserts adapter sequences into fragmented nucleic acids through transposition chemistry, substituting the polymerase-driven replication process with an enzyme-mediated insertion process that does not exhibit GC-rich region bias.
2Manufacturing precision
If multiple steps and material transfers are used in library preparation, then library quality is improved, but process complexity and cost increase
Solution Approach 1:
The invention merges multiple separate library preparation steps into a single transposome-mediated tagmentation reaction. The transposome complex simultaneously performs nucleic acid fragmentation, adapter tagging, and indexing in one step, eliminating the need for separate fragmentation, end-repair, and adapter ligation steps required by conventional methods.
Solution Approach 2:
The transposome complex serves multiple functions simultaneously: it acts as a fragmentation enzyme, an adapter delivery vehicle, and an indexing mechanism. This multi-functional approach replaces the need for multiple specialized reagents and steps, simplifying the overall workflow while maintaining library quality.
3Adaptability or versatility
If PCR amplification is used to introduce index sequences, then indexing is achieved, but additional steps and time are required
Solution Approach 1:
The invention incorporates index sequences directly into the transposome complex structure before the tagmentation reaction. This preliminary incorporation of indexing capability allows unique molecular identifiers to be attached during the initial fragmentation step, eliminating the need for subsequent separate indexing PCR amplification steps.
Solution Approach 2:
The invention combines the indexing function with the fragmentation and tagging functions in a single integrated transposome-mediated step. By merging these operations, the method achieves comprehensive indexing capability without the time penalty of sequential PCR-based indexing approaches.
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 achieves efficient, unbiased library preparation with improved indel calling and coverage in GC-rich regions, reducing time and cost while maintaining consistent insert sizes.
Implementation Method 1
a transposome complex comprising: (a) a transposase; (b) a first transposon including a 3′ transposon end sequence and a 5′ adaptor sequence; (c) a second transposon including a 5′ transposon end sequence and a 3′ adaptor sequence
Implementation Method 2
an attachment polynucleotide including: (i) an attachment adaptor sequence hybridized to one of the two adaptor sequences
Implementation Method 3
the binding element is immobilized to a solid support to provide an immobilized transposome complex
Data Source
AI summary
The present disclosure relates to methods, compositions, and kits for generating a library of tagged nucleic acid fragments without using PCR amplification, including methods and compositions for fragmenting and tagging nucleic acids (e.g., DNA) using transposome complexes immobilized on solid support.