Table of Contents
ISRN Nanotechnology
Volume 2012, Article ID 454072, 11 pages
Research Article

Evaluation of Viability and Proliferation Profiles on Macrophages Treated with Silica Nanoparticles In Vitro via Plate-Based, Flow Cytometry, and Coulter Counter Assays

1Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Building 64, Room 2086 HFD-910, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA
2Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8520, Gaithersburg, MD 20899-850, USA

Received 27 June 2012; Accepted 26 August 2012

Academic Editors: F. Grasset, A. Hu, W. Lu, and Y. Zhang

Copyright © 2012 S. Bancos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Nanoparticles (NPs) are known to interfere with many high-throughput cell viability and cell proliferation assays, which complicates the assessment of their potential toxic effects. The aim of this study was to compare viability and proliferation results for colloidal silica (SiO2 NP; 7 nm) in the RAW 264.7 mouse macrophage cell line using three different techniques: plate-based assays, flow cytometry analysis, and Coulter counter assays. Our data indicate that CellTiter-Blue, XTT, and CyQuant plate-based assays show increased values over control at low SiO2 NPs concentrations (0.001–0.01 g/L). SiO2 NPs show little-to-no interference with flow cytometry and Coulter counter assays, which not only were more reliable in determining cell viability and proliferation at low concentrations in vitro, but also identified changes in cell granularity and size that were not captured by the plate-based assays. At high SiO2 NP concentrations (1 g/L) all techniques indicated cytotoxicity. In conclusion, flow cytometry and Coulter counter identified new cellular features, and flow cytometry offered more flexibility in analyzing the viability and proliferation profile of SiO2 NP-treated RAW 264.7 cells.