MEDUSA: Maintaining Entire DNA Duplexes for Utmost Sequencing Accuracy

Area of Science:

• Genomics
• Molecular Biology
• Biotechnology

Background:

• Accurate detection of low-level genetic variants is critical for clinical care and research.
• Duplex sequencing offers high accuracy but can be compromised by DNA preparation methods that cause errors.
• Existing methods may indistinguish true mutations from base damage errors due to DNA resynthesis.

Purpose of the Study:

• To develop a method that maximizes duplex sequencing accuracy and yield by minimizing DNA resynthesis.
• To introduce MEDUSA (Maintaining Entire DNA Duplexes for Utmost Sequencing Accuracy) for enhanced genetic variant detection.

Main Methods:

• MEDUSA involves repairing and blunting fragmented double-stranded DNA (dsDNA).
• It uses apyrase to digest residual dNTPs and restricted dA-tailing to prevent resynthesis.
• The protocol is simplified, offers full genome coverage, and is compatible with various dsDNA fragmentation and library preparation kits.

Main Results:

• MEDUSA demonstrated minimal residual single-nucleotide variant frequency, close to theoretical expectations for blocked resynthesis.
• The method achieved full genome coverage and duplex yields comparable to traditional methods.
• Benchmarking was performed on sheared genomic DNA from tumor tissue, blood cells, and cell-free DNA.

Conclusions:

• MEDUSA significantly enhances duplex sequencing accuracy by minimizing false mutation discovery.
• The method enables high-breadth or high-depth sequencing applications.
• MEDUSA is a valuable tool for precise genetic variant detection in diverse DNA samples.