Simple method to remove contamination of the host DNA in parasitic crustaceans using DNA AWAY

Contamination of host DNA is a severe problem in molecular experiments on parasites. In this study, we examined a method for removing host DNA from the surface of samples using the DNA decontamination reagent DNA AWAY for DNA analysis of parasitic crustaceans, using Mothocya parvostis (Crustacea: Isopoda: Cymothoidae), and its host the Japanese halfbeak, Hyporhamphus sajori. After pereopods with host mucus attached were either untreated (control) or immersed in DNA AWAY for 1 s to 3 h, DNA was extracted from them, and 16S rRNA was amplified by PCR. In the control, host fish DNA was detected electrophoretically as bands of about 590 bp and parasite DNA as bands of about 490 bp. Parasite-derived bands were unaffected by treatment with DNA AWAY, but host-derived bands faded with longer immersion time. This method involves a simple immersion process, which could provide a practical solution for researchers struggling with host DNA contamination in their DNA sequencing of parasitic crustaceans.