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Oliveira N.C.L.,Federal University of Pernambuco | Campos-Ferreira D.S.,Federal University of Pernambuco | Nascimento G.A.,Federal University of Pernambuco | Zanforlin D.M.L.,Federal University of Pernambuco | And 3 more authors.
Forensic Science International: Genetics Supplement Series | Year: 2015

The detection and identification of human body fluids at crime scenes is usually performed using colorimetric and crystallographic tests. However, these assays may limit the samples detection during the washing steps. Currently, biosensors are emerging as alternative devices in molecular biology, combining the specificity and sensitivity of biological systems with the computing power of microprocessors. Herein, we report a preliminary study of an electrochemical biosensor able to detect DNA sequences in solutions mixed with household cleaners, aiming to simulate the effects of these chemicals on sample detection. The device was made using pencil graphite, acting as a working electrode (PGE) and an Ag/AgCl pin as a reference electrode. Single-strand DNA probes (ssDNA) were immobilized on PGE surface and the hybridization assay was performed by immersing the ssDNA-PGE electrode in a buffer solution with the target sequence under specific annealing temperature for 10. min. Samples contamination was stimulated by household cleaners by immersing dsDNA-PGE immersed in solutions containing sodium hypochlorite, alcohol and SDS for 30. min. The current peaks obtained with ssDNA-PGE and dsDNA-PGE were highly distinguishable (118.6. nA and 24.435. nA, respectively), even when dsDNA-PGE was mixed with sodium hypochloride, alcohol and detergent (17.12. nA, 35.81. nA and 69.44. nA, respectively). These findings suggest that DNA biosensors have a great potential to be used as a confirmatory test to detect human body fluids in crime scenes. © 2015 Elsevier Ireland Ltd.

Oliveira N.C.L.,Federal University of Pernambuco | Ekert M.H.F.,Federal University of Pernambuco | Souza C.A.,Laboratorio Of Pericia E Pesquisa Em Genetica Forense Lppgf | Rabelo K.C.N.,Laboratorio Of Pericia E Pesquisa Em Genetica Forense Lppgf | And 2 more authors.
Forensic Science International: Genetics Supplement Series | Year: 2015

Identification of perpetrators is crucial in criminal investigations, mainly in rape cases. Analysis of the area, victims' profile, as well as genotyping DNA markers from rapists may help to determine hotspots of the crime, in a way to prevent its recurrence. Herein, we report for the first time in Northeastern Brazil a preliminary genetic data analyses from rape cases that occurred in Pernambuco between 2012 and 2014. Moreover, the distribution of the cases, as well as a general profile of the victims were analyzed from official reports of Laboratório de Perícia e Pesquisa em Genética Forense (LPPGF-PE). The results showed that 62% of the cases are mainly located in the metropolitan area of Pernambuco. Eighty-eight percent of the victims were females and 37% were under age. Allele frequency was determined by at least 15 STRs and, in some cases, by Y-STRs and InDel markers. This study may contribute to the elucidation of rape crime investigation in the future. © 2015.

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