title: RNA and DNA aptamers in cytomics analysis.
abstract: BACKGROUND
  The systematic evolution of ligands by exponential enrichment (SELEX) technique is a combinatorial library approach in which DNA or RNA molecules (aptamers) are selected by their ability to bind their protein targets with high affinity and specificity, comparable to that of monoclonal antibodies. In contrast to antibodies conventionally selected in animals, aptamers are generated by an in vitro selection process, and can be directed against almost every target, including antigens like toxins or nonimmunogenic targets, against which conventional antibodies cannot be raised.
  
  
  METHODS
  Aptamers are ideal candidates for cytomics, as they can be attached to fluorescent reporters or nanoparticles in order to study biological function by fluorescence microscopy, by flow cytometry, or to quantify the concentration of their target in biological fluids or cells using ELISA, RIA, and Western blot assays.
  
  
  RESULTS
  We demonstrate the in vitro selection of anti-kinin B1 receptor aptamers that could be used to determine B1 receptor expression during inflammation processes. These aptamers specifically recognize their target in a Northern-Western blot assay, and bind to their target protein whenever they are exposed in the membrane.
  
  
  CONCLUSIONS
  Currently, aptamers are linked to fluorescent reporters. We discuss here the present status and future directions concerning the use of the SELEX technique in cytomics.
authors.affiliation: Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil. henning@iq.usp.br
authors.forename: Henning
authors.initials: H
authors.lastname: Ulrich
authors.forename: Antonio Henrique B
authors.initials: AH
authors.lastname: Martins
authors.forename: João Bosco
authors.initials: JB
authors.lastname: Pesquero
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D008024:Ligands; D011506:Proteins / Q000032:analysis / Q000737:chemistry* / Q000502:physiology; D040901:Proteomics / Q000379:methods; D012313:RNA / Q000737:chemistry*
chemical_list: D008024:Ligands; D011506:Proteins; D012313:RNA; D004247:DNA