Protocols for dry DNA storage and shipment at room temperature

Area of Science:

• Molecular Biology
• Genetics
• Bioinformatics

Background:

• Global DNA barcoding initiatives necessitate robust, cost-effective methods for DNA sample preservation and transport.
• Current storage protocols often rely on freezing, which is vulnerable to power failures and logistical challenges.
• Dry-state stabilization offers a potential alternative for preserving DNA extracts and PCR products.

Purpose of the Study:

• To evaluate the efficacy of three dry-state DNA stabilization systems for insect DNA.
• To compare the performance of commercial Biomatrica® DNAstable® plates, home-made trehalose, and polyvinyl alcohol (PVA) plates.
• To assess DNA integrity and PCR success over a four-year storage period at elevated temperatures (56°C and room temperature).

Main Methods:

• Insect DNA samples were stored on Biomatrica® plates, trehalose plates, and PVA plates.
• Control samples included unprotected DNA stored dry at room temperature and 56°C, and diluted samples at 4°C and -20°C.
• DNA quality was assessed via PCR amplification and selective sequencing over a 4-year interval.

Main Results:

• Biomatrica® plates demonstrated superior DNA protection at 56°C and room temperature, particularly for diluted samples.
• PVA and trehalose showed varying degrees of protection, with PVA performing better at room temperature and trehalose at 56°C.
• While -20°C storage yielded better DNA quality (longer reads, stronger signal), dry storage systems provide valuable backup protection against freezer failure.

Conclusions:

• Dry-state DNA stabilization, especially using commercial Biomatrica® plates, offers a viable strategy for preserving DNA extracts and PCR products.
• These methods facilitate the shipment of dry DNA and PCR products between global DNA barcoding facilities.
• While not replacing cold storage entirely, dry stabilization enhances sample security and logistical flexibility for large-scale biodiversity projects.