title: Effect of presumptive tests reagents on human blood confirmatory tests and DNA analysis using real time polymerase chain reaction.
abstract: Bloodstains often constitute the major physical evidence in crime investigation. Diluted blood invisible to the naked eye can be detected through presumptive tests however such tests can damage samples and prevent further processing such as DNA analysis. In this study, we compared the effects of luminol (prepared according to Weber [15]), Luminol 16(®), Bluestar(®) and benzidine for inhibition in the human antiglobulin test and the human hemoglobin immunochromatographic test and on the total human DNA concentration up to 120 days after sample treatment. Treatment with both luminol solutions and Bluestar(®) still allowed positive results for the immunologic tests, indicating non-interference with human blood confirmatory tests. However, samples treated with benzidine could not be further analyzed by serological tests. Also, DNA quantification showed that 48h after benzidine treatment, but not luminol or Bluestar solution application, sample DNA was degraded. Luminol 16(®) caused DNA degradation already at 30 days post-application. At 120 days post treatment, all samples treated with any of the agents but not untreated samples had DNA degradation.
authors.affiliation: Laboratório de Perícias, Instituto Geral de Perícias do Estado do Rio Grande do Sul, Avenida Azenha, 255 CEP 90160-000 Porto Alegre, Rio Grande do Sul, Brazil. juliana-almeida@igp.rs.gov.br
authors.forename: Juliana Piva
authors.initials: JP
authors.lastname: de Almeida
authors.forename: Nadine
authors.initials: N
authors.lastname: Glesse
authors.forename: Cristina
authors.initials: C
authors.lastname: Bonorino
mesh_terms: D001560:Benzidines / Q000737:chemistry; D001801:Blood Stains; D004247:DNA / Q000032:analysis*; D053836:DNA Degradation, Necrotic / Q000187:drug effects*; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D008165:Luminol / Q000737:chemistry; D016133:Polymerase Chain Reaction / Q000379:methods*; D012698:Serologic Tests; D013048:Specimen Handling; D013997:Time Factors
chemical_list: D001560:Benzidines; D007202:Indicators and Reagents; C029876:benzidine; D008165:Luminol; D004247:DNA