Invertebrate traps and DNA - literature review. Survey of sample preservatives compatible with DNA analysis.
A targeted literature review was carried out to investigate methods for terrestrial invertebrate sampling for use with DNA analysis techniques. The aim of the review was to investigate the current state of knowledge for the sampling and preservation of terrestrial invertebrates and compare and assess these methods. The review included studies that had been subject to peer review along with grey literature and personal communications from individuals within organisations known to carry out terrestrial invertebrate sampling. The findings of the review indicate that propylene glycol may better preserve DNA for downstream applications than ethanol despite general consensus that 100% ethanol is the best preservative, although this statement is made with caution as the sample number was small. In general, there was considerable variation between methods at every stage in the process and information which could have been useful for example biotic and abiotic factors was most often not included. Several studies did not state the concentration of the preservative used, the sampling duration, or included information on long term storage conditions, all of which would have provided valuable insight into the potential reproducibility of the studies. Options for practical method testing are given with a view to the standardisation of trapping methods currently used by Natural England.