Ensilication preserves high-molecular weight native DNA for clinical long-read sequencing

Area of Science:

• Genomics
• Molecular Biology
• Biotechnology

Background:

• Long-read DNA sequencing offers simultaneous detection of genetic variants and epigenetic modifications.
• Current preservation methods require cold-chain infrastructure, limiting accessibility in resource-limited settings and field research.

Purpose of the Study:

• To evaluate ensilication as a method for preserving DNA integrity and sequencing performance at ambient temperatures.
• To demonstrate the utility of ensilicated DNA for diagnostic-quality long-read sequencing in real-world patient samples.

Main Methods:

• DNA samples were encapsulated within silica matrices (ensilication).
• Ensilicated DNA was subjected to ambient temperature storage, handling, and accelerated weathering tests.
• Sequencing performance of ensilicated DNA was compared to frozen controls using Genome-in-a-Bottle (GIAB) reference samples.
• Ensilicated patient samples underwent native long-read sequencing for variant and methylation analysis.

Main Results:

• Ensilication preserved DNA integrity comparable to -80 °C freezing at ambient temperatures.
• Ensilicated DNA maintained sequencing performance and showed resistance to degradation under simulated long-term storage and handling.
• Native long-read sequencing of ensilicated patient samples successfully identified a de novo variant and diagnostic methylation episignatures.

Conclusions:

• Ensilication effectively preserves DNA for diagnostic-quality long-read sequencing without cold-chain requirements.
• This method significantly expands access to advanced genomic technologies in resource-limited environments and field applications.