A practical guide to sample preservation and pre-PCR processing of aquatic environmental DNA

Area of Science:

• Ecology
• Molecular Biology
• Environmental Science

Background:

• Environmental DNA (eDNA) is increasingly utilized for ecological assessments and species identification.
• Standardized protocols for eDNA sample collection and processing are lacking, creating challenges for researchers.
• A growing body of literature exists, making it difficult to determine optimal eDNA methodologies.

Purpose of the Study:

• To review common techniques for collecting, preserving, and extracting metazoan eDNA from water samples.
• To compare various experimental methods and highlight challenges in eDNA research.
• To provide guidance for researchers integrating eDNA approaches into their studies.

Main Methods:

• Focused on experimental studies comparing different eDNA collection, preservation, and extraction techniques.
• Reviewed methods for metazoan eDNA from aquatic environments.
• Synthesized findings on challenges and best practices in eDNA analysis.

Main Results:

• No single "one-size-fits-all" protocol is universally applicable for eDNA analysis.
• A common effective method involves filtering water (pore size based on turbidity), preserving filters in Longmire's buffer, and using kits like DNeasy Blood & Tissue for extraction.
• Optimizing protocols for specific research systems is crucial for generating high-quality eDNA data.

Conclusions:

• The reviewed methods provide a strong foundation for effective eDNA collection and processing.
• Researchers should adapt and test protocols based on their specific environmental DNA study system.
• Standardization and optimization are key to advancing the reliability and application of eDNA techniques.