Morphological confocal microscopy in arthropods and the enhancement of autofluorescence after proteinase K extraction.

Procedures to study the molecular and morphological characteristics of microscopic organisms are often incompatible with each other. Therein, the realization of alternatives that make the characterization of these features compatible and simultaneously permit the deposition of the original material as a voucher sample into a reference collection is one of the foremost goals of biodiversity studies. In this study, we show that genomic extraction does not necessarily compromise the detailed study of the external morphology of microscopic organisms, and to do so, we used a group of aquatic mites (Acari, Hydrachnidia) as a test group. Hydrachnidia morphology is difficult to study when specimens have been stored in pure ethanol; however, proteinase K extraction leaves them flexible and easy to dissect, while, at the same time, maintaining all of their diagnostic features intact. Furthermore, autofluorescence is significantly enhanced after proteinase extraction. Our study was conducted with aquatic mites that were stored in absolute ethanol in the field and processed for DNA extraction using a Qiagen QIAamp minikit. Before and after molecular extraction, a laser scanning confocal microscopy morphological examination was carried out.