title: The Yin and Yang of Microrna Assay Methods.
abstract: OBJECTIVE
  microRNA assessments in biological samples can be performed by different methods that mainly rely on hybridization process, qPCR or RNA sequencing. With the aim to detect and validate microRNA biomarkers in tumor samples, we challenged the consistency of the quantitative results obtained with the different methods.
  
  
  METHODS
  We measured microRNA concentrations in several biological samples such as cultured tumor cells or tumor tissues (frozen tissues or FFPE samples) using different microRNA assay methods, in particular hybridization to AffymetrixTM arrays, qPCR and digital droplet qPCR (BioradTM) based on Taqman microRNA assays (Life TechnologiesTM). We also compared our results to other data that have been obtained with different technical approaches and available in the literature.
  
  
  RESULTS
  We found poor consistency for the microRNA amounts measured in the samples assayed by the different methods. Both technical platforms and microRNA assays protocols may be responsible for the observed inconsistencies.
  
  
  CONCLUSIONS
  When assaying microRNAs for clinical purpose or fundamental researches it seems necessary to keep in mind the specific pitfalls of all the microRNA detection methods such as those we disclose here. Obviously, valid inter sample comparisons and meaningful multicenter studies can only be obtained when microRNA assessments are strictly performed with identical technical approaches and reagents.
authors.forename: Audrey
authors.initials: A
authors.lastname: Guttin
authors.forename: Hélène
authors.initials: H
authors.lastname: Ipas
authors.forename: Maud
authors.initials: M
authors.lastname: Barbado
authors.forename: Catherine
authors.initials: C
authors.lastname: Mouret
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Garcion
authors.affiliation: Grenoble Institut des Neurosciences, Chemin Fortuné Ferrini, F-38000 Grenoble, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Issartel