Oligonucleotide Fragment Hairpin Structure for Selective Amplification
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Solution Overview
Problem
Current methods for selective amplification of mutant-type nucleic acid sequences in tumor cells are hindered by low selectivity, as wild-type variants often dominate the signal, making it difficult to detect small quantities of mutant variants in a background of abundant wild-type sequences.
Innovation Solution
An oligonucleotide fragment with a primer region and a variant recognition region covalently linked, where the variant recognition region forms a hairpin structure with a nucleic acid double strand-stabilizing factor, preventing amplification of non-target sequences by forming a stable hairpin structure that inhibits further amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional selective amplification methods (PCR clamping, RFLP-PCR, digital PCR) are used to detect mutant-type variants, then detection capability is improved, but selectivity deteriorates because wild-type variants dominate the signal
Solution Approach 1:
The oligonucleotide is divided into two functional segments: a primer region for binding to the target sequence and a variant recognition region for specific mutant detection. This segmentation allows each region to perform its specialized function independently, with the variant recognition region forming a hairpin structure that selectively inhibits wild-type amplification while allowing mutant amplification
Solution Approach 2:
The variant recognition region is pre-configured in a hairpin structure before the amplification reaction begins. This preliminary structural arrangement ensures that the oligonucleotide is primed to selectively bind and inhibit wild-type sequences, creating a built-in selectivity mechanism that operates throughout the amplification process without requiring additional selective steps
2Reliability
If the oligonucleotide forms a hairpin structure with the variant recognition region, then selectivity is improved by inhibiting wild-type amplification, but amplification efficiency may deteriorate due to structural constraints
Solution Approach 1:
The oligonucleotide structure is designed to be dynamic rather than static. The hairpin structure in the variant recognition region can open and close based on the presence of mutant versus wild-type sequences. When binding to mutant sequences, the hairpin opens to allow amplification; when binding to wild-type sequences, the hairpin remains closed to inhibit amplification, thus maintaining high amplification efficiency for mutants while achieving selectivity
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
This approach achieves high selectivity, allowing for efficient detection of trace amounts of mutant variants by inhibiting the amplification of wild-type variants, reducing false positives and improving detection accuracy in tumor diagnostics and genotyping.
Implementation Method 1
the variant recognition region forming a hairpin structure with a sequence generated from extension of the primer region
Implementation Method 2
the variant recognition region forming a hairpin structure with a sequence generated from extension of the primer region
Implementation Method 3
the variant recognition region being covalently linked with a nucleic acid double strand-stabilizing factor
Data Source
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AI summary
Provided is a method for selective amplification of a variant of a target nucleic acid sequence. Also provided is an oligonucleotide fragment with a particular structure which is used in the said method, the oligonucleotide fragment comprises a primer region and a variant recognition region.