Polymerase Activity Normalization with Fish DNA for Lot Consistency

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Variability in the activity of Taq DNA polymerase between different manufacturers and lots leads to inconsistent results in nucleic acid quantification assays, particularly in methods like QuARTS, affecting the accuracy of copy number calculations.

Innovation Solution

Incorporating purified, exogenous non-target DNA, such as from fish species like herring or salmon, into the reaction mixture, along with a DNA polymerase, flap endonuclease, and a hairpin oligonucleotide, to stabilize the reaction and minimize enzyme variability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Taq DNA polymerase from different manufacturers or lots is used, then the assay can be performed with available enzymes, but the activity variability leads to inconsistent standard curves and inaccurate quantification

Engineering Contradiction:

Improveconsistency of polymerase activityVSAvoidaccuracy of copy number calculation

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the physical-chemical parameters of the reaction system by adding purified non-target DNA from fish species. This addition modifies the reaction conditions in a way that normalizes polymerase activity across different lots, allowing accurate quantification without requiring each polymerase batch to be individually calibrated.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Purified non-target DNA from fish species acts as an intermediary substance that mediates between the variable polymerase enzyme and the target nucleic acid. This intermediary component absorbs or compensates for the polymerase variability, ensuring consistent amplification efficiency and standard curve characteristics across different enzyme lots.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If hot start technology is implemented to suppress spurious reactions, then reaction specificity is improved, but the activity of Taq enzyme becomes more difficult to assay and adjust

Engineering Contradiction:

Improvespecificity of amplification reactionVSAvoiddifficulty of assaying polymerase activity

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The addition of fish DNA changes the reaction parameters in a way that reveals or normalizes polymerase activity even in hot start systems. This parameter change allows vendors to assay and adjust enzyme activity despite the presence of hot start technology that suppresses background reactions.

Inventive Principle:

Principle #35Parameter changes

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

Stabilizes the reaction by reducing the differences in standard curve slopes and intercepts, thereby improving the accuracy of nucleic acid quantification by compensating for enzyme lot-to-lot variability.

Implementation Method 1

Methodology Applied

Scientific EffectEnzyme-substrate interaction: Enzyme

Data Source

PatentUS12385087B2Normalization of polymerase activity

Publication Date: 2025.08.12 EXACT SCIENCES CORP

AI summary

Provided herein is technology relating to the amplification-based detection of nucleic acids and particularly, but not exclusively, to methods and compositions for minimizing variability in the activity between different samples or manufacturing lots of DNA polymerases, such as Taq DNA polymerase.