Compilation of real-time PCR conditions toward the standardization of environmental DNA methods

The recent development of the environmental DNA (eDNA) technique has dramatically facilitated investigations of the distribution and abundance of macroorganisms in the natural environment. Various real-time polymerase chain reaction (PCR)-based methods have been proposed for the detection and quantification of eDNA by independent researchers or groups. Although several eDNA reviews have outlined the critical requirements for experimental processes and provided guidelines for best practice, clear standardization of eDNA protocols is lacking. Here, we collected the PCR conditions of previous eDNA studies using real-time PCR (n = 190), that is, the volume of the DNA template, PCR cycles, number of PCR replicates and PCR inhibition tests. Then, we synthesized the current development of real-time PCR techniques for eDNA studies. Our synthesis has identified the critical issues that need to be addressed to design standardized protocols for eDNA monitoring that will enable broader uptake of eDNA technology.

Automated summary

The recent development of environmental DNA (eDNA) technique has greatly facilitated the study of distribution and abundance of macroorganisms in natural environment. Although various real-time polymerase chain reaction (PCR)-based methods have been proposed, clear standardization of eDNA protocols is still lacking.