Mitochondrial 6 mA PCR Detection for Accurate Age Estimation
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Solution Overview
Problem
Existing DNA methylation detection technologies are costly, time-consuming, and prone to artifacts, and they cannot accurately determine the relative methylation levels at specific genomic sites, limiting their application in medical and forensic diagnostics.
Innovation Solution
A PCR-based method using a 6 mA-specific restriction endonuclease and linker DNA fragment amplification to quantify relative 6 mA levels at specific mitochondrial DNA sites, allowing for accurate age determination and lifespan prediction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing DNA methylation detection technologies are used, then methylation status can be detected, but the measurement is costly, time-consuming, and cannot accurately determine relative methylation levels at specific genomic sites
Solution Approach 1:
The method segments the detection process into distinct steps: (1) digestion with 6 mA-specific restriction endonuclease to isolate methylated sites, (2) ligation of adapter DNA fragments to create amplifiable structures, and (3) PCR amplification using primers specific to the adapter sequence. This segmentation allows accurate quantification of relative 6 mA levels at specific genomic sites while simplifying each individual step.
Solution Approach 2:
The patent introduces adapter DNA fragments as intermediary molecules that bridge the methylated genomic DNA and the PCR amplification system. These adapters contain known sequences that serve as binding sites for PCR primers, enabling accurate and specific amplification of methylated regions without requiring complex direct detection methods.
2Measurement precision
If existing DNA methylation detection technologies are used, then methylation status can be detected, but the process is time-consuming
Solution Approach 1:
The method performs preliminary digestion of genomic DNA with 6 mA-specific restriction endonuclease before PCR amplification. This preliminary action selectively cuts only at methylated sites, pre-enriching the template for subsequent amplification and eliminating the need for time-consuming whole-genome sequencing or complex library preparation steps.
Solution Approach 2:
The patent replaces complex mechanical sequencing systems with a biochemical amplification system. Instead of using sophisticated instruments for direct methylation detection, the method uses enzymatic digestion followed by PCR amplification, which can be performed in standard molecular biology laboratories with常规 equipment, significantly reducing detection time.
3Reliability
If existing DNA methylation detection technologies are used, then methylation status can be detected, but artifacts are frequently generated
Solution Approach 1:
The method applies local quality control by using 6 mA-specific restriction endonucleases that recognize and cut only at specific methylated sequences. This site-specific approach ensures that only truly methylated regions are amplified, eliminating artifacts that arise from non-specific detection methods. The adapter ligation and PCR priming are also localized to specific regions, further ensuring accuracy.
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
The method provides precise age determination with a 2-3 year margin of error and early detection of neurodegenerative processes, enabling effective forensic analysis and lifestyle adjustments.
Implementation Method 1
individual genomes isolated from a tissue sample examined are digested with a 6 mA-dependent restriction endonuclease
Implementation Method 2
the resulting genomic fragments are then ligated to a linker DNA fragment called adapter
Implementation Method 3
a sequence-specific PCR- (polymerase chain reaction) based DNA amplification is achieved by using a forward primer
Data Source
AI summary
A molecular biology method, by which relative (normalized to an internal control) N6-methyladenine (6 mA) level at a selected site of the mitochondrial (mt) DNA (deoxyribonucleic acid) (mtDNA) in a tissue sample is accurately determined, and this level is projected to a reference “relative mtDNA 6 mA level-age” curve constructed earlier is described. On the reference curve, relative mtDNA 6 mA levels reversely correlate with age; the higher the relative mtDNA 6 mA level, the younger the individual analyzed. Where the value of the relative mtDNA 6 mA level cuts the reference curve, this intersection assigns the corresponding age on the X axis. The reference curve was previously established by determining 6 mA levels at a specific mtDNA site in a large (>1000) number of healthy individuals with known age. The accuracy of the measurement depends on the accuracy of the method by which mtDNA 6 mA level is determined. The method is also suitable for predicting expected lifespan in an individual with known age. The invention relies on our recent biological finding that 6 mA levels at specific mtDNA regions negatively correlate with (is reversely proportional to) the age of the individual analyzed.