HotSHOT Plus ThermalSHOCK, a new and efficient technique for preparation of PCR-quality mite genomic DNA

The present study adapted the HotSHOT method, a technique which has been successfully applied on different kinds of tissues, to studies of Sarcoptes. Some modifications of this technique were made which allowed the quick preparation of PCR-quality Sarcoptes genomic DNA (gDNA), namely applying sodium hydroxide as a substrate for three cycles of thermal shock, followed by a short incubation and pH adjustment with a Tris solution (HotSHOT Plus ThermalSHOCK). The performance of this technique was tested by amplifying a approximately 450-bp rDNA fragment of the second internal transcribed spacer (ITS-2) and by multi-locus genotyping using ten microsatellites on 520 individual Sarcoptes samples. No difference in performance was observed between gDNA samples prepared using the HotSHOT Plus ThermalSHOCK technique and those prepared using a commercial kit utilizing proteinase K digestion. The results demonstrated that the HotSHOT Plus ThermalSHOCK technique is time-saving, economic, and easily automatable for the preparation of PCR-quality mite gDNA, which has implications for studying the molecular biology of mites with human and animal health significance. Although tested in the present study using Sarcoptes mites as a model, this technique may find broad applicability in extraction of gDNA from other parasites with small sizes and hard bodies.