Methods for extraction and ex-vivo experimentation with the most complex human commensal, Demodex spp.

Demodex spp. mites are the most complex organisms of the human skin microbiome and were discovered more than 175 years ago, yet only little basic research is published about them. As they can be pathophysiologically relevant ectoparasites associated with rosacea, pityriasis folliculorum, and other inflammatory skin diseases, more research should be encouraged. Being a large microorganism or a tiny animal, there are no established basic methods to handle these mites. Here, we describe techniques enabling the extraction of Demodex mites from human skin, their analysis in different ex-vivo settings, the lysis of their exoskeleton, their preservation by freezing, and observation microscopically using specific fluorescent dyes or their inherent autofluorescence. These procedures should facilitate future Demodex research and fuel further the generation of knowledge. Furthermore it is intended to ultimatively enable the mite's cultivation in vitro and reveal its pathophysiological mechanisms.