ARMS Primers for EGFR Mutation Detection Sensitivity
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Solution Overview
Problem
Current methods for detecting EGFR mutations in cancer, particularly lung cancer, face challenges due to low tumor representation in biopsy samples and limited sensitivity of nucleotide sequencing, which requires expensive and time-consuming sample enrichment processes.
Innovation Solution
The use of the amplification refractory mutation system (ARMS) with mutation-specific primers and a kit comprising polynucleotides, including a quencher and fluorophore group, to selectively amplify specific sequence variants, enhancing detection sensitivity and avoiding carry-over contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If nucleotide sequencing is performed to identify a wide range of EGFR mutations, then mutation detection coverage is improved, but detection sensitivity deteriorates due to low prevalence of mutations in heterogeneous tumor samples
Solution Approach 1:
The invention divides the detection approach into two stages: first using ARMS PCR with mutation-specific primers to selectively amplify and detect known mutations with high sensitivity, then using nucleotide sequencing as a complementary method to discover novel mutations. This segmentation allows each method to operate in its optimal performance range.
Solution Approach 2:
The invention changes the detection parameter from direct sequencing of heterogeneous samples to selective amplification of mutant alleles followed by detection. By using ARMS PCR conditions optimized for detecting low-abundance mutant sequences, the system achieves detection sensitivity below 1% mutation prevalence while maintaining broad mutation coverage through multiple primer sets.
2Measurement precision
If sample enrichment is performed to increase tumor material concentration, then detection sensitivity is improved, but time consumption and cost increase
Solution Approach 1:
The invention replaces mechanical sample enrichment procedures (such as manual tumor cell isolation or physical separation techniques) with a molecular-based enrichment approach using ARMS PCR. The mutation-specific primers selectively amplify mutant DNA sequences directly from heterogeneous samples, achieving effective enrichment without time-consuming physical manipulation steps.
3Measurement precision
If PCR cycle numbers are increased to improve detection sensitivity, then mutation detection capability is improved, but carry-over contamination risk increases
Solution Approach 1:
The invention introduces mutation-specific primers as intermediaries that selectively bind to mutant sequences. This specificity acts as a filter that prevents amplification of wild-type sequences and reduces the risk of carry-over contamination from previous PCR reactions, even when high cycle numbers are used to detect low-abundance mutants.
4Ease of operation
If restriction fragment length polymorphism is used for mutation detection, then method simplicity is improved, but detection sensitivity deteriorates due to low cycle number limitations
Solution Approach 1:
The invention inverts the traditional approach by using PCR amplification with mutation-specific primers as the primary detection method rather than using restriction enzymes. This reversal allows for higher PCR cycle numbers to be used, dramatically improving detection sensitivity while maintaining operational simplicity through a single-step amplification reaction.
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 allows for high detection sensitivity and specificity of EGFR mutations, even in low tumor samples, providing a robust and accurate method for diagnosing EGFR mutations without the need for DNA sequencing or radioisotopes, thus improving cancer diagnosis and treatment monitoring.
Implementation Method 1
detecting hybridisation of the polynucleotide to the nucleic acid sample wherein hybridisation indicates the presence or absence of a mutation
Implementation Method 2
the amplification refractory mutation system (ARMS) with mutation-specific primers and a kit comprising polynucleotides, including quencher and fluorophore groups, to selectively amplify and detect EGFR mutations
Implementation Method 3
a kit comprising polynucleotides, including quencher and fluorophore groups
Data Source
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AI summary
A polynucleotide primer comprising at least 75% of the ten nucleotides at the 3' end of the following primer sequence, or a sequence complementary thereto: SEQ. ID NO. 21.