Long duration, room temperature preservation of filtered eDNA samples

The use of environmental DNA is a rapidly evolving approach for surveillance and detection of species. Often water samples are collected in the field and then immediately cooled, filtered, and the resulting filters are stored in freezers to preserve the DNA for subsequent analyses. Recently it was shown that filtered samples could be stored at room temperature for 14 days without any discernable loss in the total DNA. However, for many conservation applications, particularly in remote settings with limited capacity to freeze samples, it would be advantageous to store samples at room temperature for longer periods of time. Here we test for significant loss of DNA yield from storage of polycarbonate track etched filters in Longmire’s lysis buffer at room temperature (20 °C) for 150 days.