Multiplexed PCR Primer Mass Extension Optimization
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Solution Overview
Problem
Current multiplex polymerase chain reaction (PCR) and primer mass extension methods face challenges with poor sensitivity, specificity, and high costs due to issues like spurious amplification products and preferential amplification of certain targets, limiting their efficiency and throughput for genotyping.
Innovation Solution
Optimized methods for performing homogeneous primer mass extension assays, including optimized PCR amplification and primer mass extension reactions, which allow for high-level multiplexing (up to 50-plex) with improved sensitivity and specificity, using specific MgCl2 concentrations and primer pair combinations to enhance robust PCR amplification while maintaining compatibility with mass spectrometry analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple primer pairs are included in the same PCR reaction to amplify two or more target sequences, then the throughput and efficiency of genotyping are improved, but the sensitivity and specificity deteriorate due to spurious amplification products and preferential amplification of certain targets
Solution Approach 1:
The patent optimizes PCR reaction parameters including MgCl2 concentration (1.5-2.5 mM), primer concentrations (50-200 nM for amplification primers, 25-100 nM for extension primers), and dNTP concentrations to enable high-level multiplexing (10-50 targets) while maintaining amplification reliability and preventing spurious products
Solution Approach 2:
The patent employs target-specific primer pairs with locally optimized sequences and concentrations for each target region, allowing differential amplification efficiency control for individual targets within the multiplex reaction, thereby preventing preferential amplification while maintaining overall sensitivity
2Loss of time
If more than one primer pair is used in multiplex PCR, then the time and effort savings are achieved, but the overall yield of amplified targets decreases due to competition for reagents and preferential amplification
Solution Approach 1:
The patent uses a universal master mix formulation containing optimized concentrations of MgCl2, dNTPs, and polymerase that supports simultaneous amplification of multiple targets (10-50 targets) in a single reaction, ensuring equitable reagent distribution and maintaining high overall yield across all targets
Solution Approach 2:
The patent implements dynamic concentration optimization where primer and dNTP concentrations are adjusted based on the number of targets being amplified, with specific formulas provided for calculating optimal concentrations to maintain high yield across varying multiplex levels
3Productivity
If high-level multiplexing (up to 50-plex) is achieved through optimized PCR conditions, then the cost per genotype is reduced and throughput is increased, but the complexity of optimizing reaction conditions increases
Solution Approach 1:
The patent provides specific parameter ranges for MgCl2 (1.5-2.5 mM), primer concentrations (50-200 nM), and dNTP concentrations that enable high-level multiplexing without requiring extensive optimization experiments, thereby reducing the complexity of condition setup while maintaining high throughput
Solution Approach 2:
The patent provides pre-optimized master mix formulations and concentration calculation formulas that allow researchers to set up high-level multiplex reactions (10-50 targets) without performing extensive optimization experiments, thereby reducing time and complexity while achieving high throughput
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
These methods significantly increase the throughput and reduce the cost per genotype by achieving high accuracy in genotyping multiple polymorphic loci, with at least 60% of attempted genotypes determined, while maintaining the quality of mass spectrometry analysis.
Implementation Method 1
The addition of a DNA polymerase along with a preselected mixture of terminator nucleotides (e.g., ddNTPs) and non-terminator nucleotides (dNTPs), allows extension of the primer up to, or through, the polymorphic site
Implementation Method 2
The speed and accuracy of matrix-assisted desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) offers a solution for high-throughput genotyping
Implementation Method 3
matrix-assisted desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)
Implementation Method 4
The hME assay is based upon annealing of an oligonucleotide primer adjacent to the SNP of interest
Data Source
AI summary
Provided herein are optimized methods for performing multiplexed detection of a plurality of sequence variations. Also provided are methods for performing multiplexed amplification of target nucleic acid.