A self-preserving, partially biodegradable eDNA filter

1. eDNA studies often rely on water filtration in the field and immediate sample preservation to prevent DNA degradation during sample transport. However, filter membrane transfer steps for preservation can increase risk of sample contamination and the reliance on typical single-use filter housings produces significant plastic waste. 2. We created a new eDNA filter housing (compatible with any suction pump) partially comprised of a biodegradable, hydrophilic material that functions to automatically preserve captured eDNA via desiccation – no filter membrane transfer steps, no chemical or cold storage required. 3. We tested the self-preservation capabilities of the desiccating filter housings by filtering replicate samples in an eDNA mesocosm study and compared with ethanol preservation. Self-preserving filters were placed back into original packaging for storage, and samples for both preservation methods were kept at room temperature until extraction at prescribed time points (11 days, ...