Number of Nanoparticles per Cell through a Spectrophotometric Method - A key parameter to Assess Nanoparticle-based Cellular Assays Unciti-Broceta, Juan Diego Cano-Cortés, Victoria Altea-Manzano, Patricia Pernagallo, Salvatore Díaz Mochón, Juan José Sánchez Martín, Rosario María Nanoparticles Biomarker research Engineered nanoparticles (eNPs) for biological and biomedical applications are produced from functionalised nanoparticles (NPs) after undergoing multiple handling steps, giving rise to an inevitable loss of NPs. Herein we present a practical method to quantify nanoparticles (NPs) number per volume in an aqueous suspension using standard spectrophotometers and minute amounts of the suspensions (up to 1 μL). This method allows, for the first time, to analyse cellular uptake by reporting NPs number added per cell, as opposed to current methods which are related to solid content (w/V) of NPs. In analogy to the parameter used in viral infective assays (multiplicity of infection), we propose to name this novel parameter as multiplicity of nanofection. 2015-06-22T07:00:38Z 2015-06-22T07:00:38Z 2015 journal article Unciti-Broceta, J.D.; et al. Number of Nanoparticles per Cell through a Spectrophotometric Method - A key parameter to Assess Nanoparticle-based Cellular Assays. Scientific Reports, 5: 10091 (2015). [http://hdl.handle.net/10481/36690] 2045-2322 http://hdl.handle.net/10481/36690 10.1038/srep10091 eng info:eu-repo/grantAgreement/EC/FP7/294142 http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Nature Publishing Group