title: Structural restoration of nematodes and acanthocephalans fixed in high percentage alcohol using DESS solution and rehydration.
abstract: Ninety-five percent ethanol is the most widely used field and laboratory preservative for nematodes and other helminth specimens intended for use in molecular systematics. Preservation of nematodes in high-concentration alcohols results in structural dehydration artifacts, including shrinkage and body surface distortions sufficient to obscure features required for morphological identification and analysis, thereby compromising precise morphometrics. However, treating dehydrated nematodes using a solution of DMSO, disodium EDTA, and NaCl, followed by rehydration in water produces marked improvements in specimen shape and surface features, resulting from diffusion of water into the tissues and pseudocoelom as the internal salt concentration is reduced. Following rehydration, tissue samples can be obtained for molecular research and individuals can be fixed for morphological examination. This treatment method is demonstrated for species of 3 nematode genera that vary substantially in body size ( Baylisascaris , Uncinaria , and Bidigiticauda ). The method also works on nematodes that have been cut in half, provided the individuals are large enough to be folded and clamped during treatment. This method appears promising for other helminths, although for an acanthocephalan, the treatment restored the body surface but failed to reverse the retracted proboscis.
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
authors.forename: Soraya
authors.initials: S
authors.lastname: Naem
authors.forename: Christopher
authors.initials: C
authors.lastname: Pagan
authors.forename: Steven A
authors.initials: SA
authors.lastname: Nadler
mesh_terms: D000049:Acanthocephala / Q000033:anatomy & histology* / Q000187:drug effects / Q000235:genetics; D000723:Ancylostomatoidea / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics; D000818:Animals; D001199:Ascaridoidea / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics; D018509:DNA, Helminth / Q000187:drug effects; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology*; D000431:Ethanol / Q000009:adverse effects; D005404:Fixatives / Q000009:adverse effects*; D009348:Nematoda / Q000033:anatomy & histology* / Q000187:drug effects / Q000235:genetics; D011309:Preservation, Biological / Q000592:standards; D012965:Sodium Chloride / Q000494:pharmacology*; D012996:Solutions
chemical_list: D018509:DNA, Helminth; D005404:Fixatives; D012996:Solutions; D000431:Ethanol; D012965:Sodium Chloride; D004492:Edetic Acid; D004121:Dimethyl Sulfoxide