title: A nanodiagnostic colorimetric assay for 18S rRNA of Leishmania pathogens using nucleic acid sequence-based amplification and gold nanorods.
abstract: OBJECTIVE
  We describe here a nanodiagnostic colorimetric assay for 18S rRNA of Leishmania pathogens that uses nucleic acid sequence-based amplification (NASBA) and gold nanorods (GNRs).
  
  
  METHODS
  NASBA primers targeting 18S rRNA were used for amplification of RNA in an isothermal process. The electrostatic interactions between the phosphate groups of the RNA amplicons and the cetyl trimethylammonium bromide layer on the GNRs resulting in their aggregation. This phenomenon changes the color of the GNR solution from red to purple.
  
  
  RESULTS
  Our data showed 100% sensitivity and 80% specificity with the colorimetric assay compared with results using reverse transcription polymerase chain reaction.
  
  
  CONCLUSIONS
  The nanodiagnostic method we describe simplifies the detection of NASBA amplicons without the need for gel electrophoresis.
authors.affiliation: Department of Medical Biotechnology, Faculty of Advanced Medical Technologies, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Niazi
authors.forename: Oghol-Niaz
authors.initials: ON
authors.lastname: Jorjani
authors.forename: Hassan
authors.initials: H
authors.lastname: Nikbakht
authors.forename: Pooria
authors.initials: P
authors.lastname: Gill
mesh_terms: D003124:Colorimetry; D017931:DNA Primers; D006046:Gold; D006801:Humans; D007891:Leishmania / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D007896:Leishmaniasis / Q000175:diagnosis*; D050997:Nanomedicine / Q000379:methods*; D043942:Nanotubes; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D021161:Self-Sustained Sequence Replication; D012680:Sensitivity and Specificity
chemical_list: D017931:DNA Primers; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S; D006046:Gold