Adapter QC Nucleosides for Accurate DNA Modification Detection

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Solution Overview

Problem

Existing single-nucleotide resolving assays for detecting epigenetic variants or nucleoside modifications suffer from false positive and false negative signals due to incomplete or erroneous conversion of nucleosides, particularly in methods like bisulfite and TAPS, leading to inaccurate methylation assessments.

Innovation Solution

Incorporating quality control nucleosides in adapters that maintain or alter base pairing specificity differently from the DNA sample nucleosides, allowing for the detection of suboptimal conversion and subsequent correction of false signals through sequence analysis and weighting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conversion procedure is applied to detect modified nucleosides, then detection capability is improved, but false positive and false negative signals increase due to incomplete or erroneous conversion

Engineering Contradiction:
Improvedetection accuracyVSAvoidsignal reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary conversion step that transforms modified nucleosides into detectable forms with altered base-pairing specificity. This intermediary conversion allows indirect detection of modifications while enabling quality control measures to assess conversion completeness and correct false signals through control nucleotides and computational methods

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements feedback mechanisms by incorporating control nucleotides in adapters that undergo the same conversion procedure as sample nucleotides. The conversion status of control nucleotides provides feedback on conversion efficiency, enabling identification and correction of false positive and false negative signals in the methylation detection results

Inventive Principle:
Principle #23Feedback

2Reliability

If quality control nucleosides are incorporated in adapters, then false signal detection is improved, but adapter sequence complexity increases

Engineering Contradiction:
Improvesignal reliabilityVSAvoidadapter complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the adapter sequence into distinct functional regions: control nucleotide regions and sample binding regions. This segmentation allows the control nucleotides to independently monitor conversion status without interfering with sample nucleotide detection, managing complexity through functional separation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adapters serve multiple functions simultaneously: they facilitate sample nucleotide binding, undergo conversion procedure, provide control nucleotides for quality monitoring, and enable sequencing. This multi-functionality reduces the need for separate control mechanisms, managing complexity through integrated design

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

Enhances the accuracy of methylation detection by identifying and correcting false positives and negatives, ensuring reliable interpretation of methylation data.

Implementation Method 1

the conversion procedure is selected to change the base pairing specificity of quality control nucleosides in the adapters

Methodology Applied
Scientific EffectBisulfite conversion:

Implementation Method 2

change their base-pairing specificity

Methodology Applied
Scientific EffectBase pairing specificity change:

Data Source

PatentEP4426858B1Quality control method
Publication Date: 2026.04.08 GUARDANT HEALTH INC
  • EP4426858B1 patent drawingFigure 1
  • EP4426858B1 patent drawingFigure 2
  • EP4426858B1 patent drawingFigure 3

AI summary

Provided herein are methods for monitoring false negative and/or false positive detection of modified nucleosides in DNA in a sample using a base-pairing conversion procedure. The methods use nucleosides having known nucleoside identity and known modification status in adapters ligated to the DNA. In certain aspects, the disclosure relates to methods for improving the quality control of such methods.