title: Evaluation of DNA typing as a positive identification method for soft and hard tissues immersed in strong acids.
abstract: Identification of human remains can be hindered by several factors (e.g., traumatic mutilation, carbonization or decomposition). Moreover, in some criminal cases, offenders may purposely adopt various expedients to thwart the victim's identification, including the dissolution of body tissues by the use of corrosive reagents, as repeatedly reported in the past for Mafia-related murders. By means of an animal model, namely porcine samples, we evaluated standard DNA typing as a method for identifying soft (muscle) and hard (bone and teeth) tissues immersed in strong acids (hydrochloric, nitric and sulfuric acid) or in mixtures of acids (aqua regia). Samples were tested at different time intervals, ranging between 2 and 6h (soft tissues) and 2-28 days (hard tissues). It was shown that, in every type of acid, complete degradation of the DNA extracted from soft tissues preceded tissue dissolution and could be observed within 4h of immersion. Conversely, high molecular weight DNA amenable to STR analysis could be isolated from hard tissues as long as cortical bone fragments were still present (28 days for sulfuric acid, 7 days for nitric acid, 2 days for hydrochloric acid and aqua regia), or the integrity of the dental pulp chamber was preserved (7 days, in sulfuric acid only). The results indicate that DNA profiling of acid-treated body parts (in particular, cortical bone) is still feasible at advanced stages of corrosion, even when the morphological methods used in forensic anthropology and odontology can no longer be applied for identification purposes.
authors.affiliation: Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università di Torino, Piazza Polonia 94, 10126 Torino, Italy. Electronic address: carlo.robino@unito.it.
authors.forename: C
authors.initials: C
authors.lastname: Robino
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 7, 10125 Torino, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pazzi
authors.affiliation: Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università di Torino, Piazza Polonia 94, 10126 Torino, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Di Vella
authors.affiliation: AOU Careggi, SOD Genetica Medica, Largo Brambilla 3, 50134 Firenze, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Martinelli
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 7, 10125 Torino, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Mazzola
authors.affiliation: AOU Careggi, SOD Genetica Medica, Largo Brambilla 3, 50134 Firenze, Italy.
authors.forename: U
authors.initials: U
authors.lastname: Ricci
authors.affiliation: ASL T02 Regione Piemonte, SC Medicina Legale, Via Pacchiotti 4, 10146 Torino, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Testi
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 7, 10125 Torino, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Vincenti
mesh_terms: D000143:Acids; D000818:Animals; D001842:Bone and Bones / Q000737:chemistry*; D004247:DNA / Q000032:analysis; D016172:DNA Fingerprinting / Q000379:methods*; D018732:Forensic Anthropology; D023421:Models, Animal; D016133:Polymerase Chain Reaction; D013552:Swine; D014070:Tooth / Q000737:chemistry*
chemical_list: D000143:Acids; D004247:DNA
keywords: Bone; DNA; Forensic genetics; Short Tandem Repeat; Strong acids; Teeth