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Measuring the Size of Nanoparticles Using Transmission Electron Microscopy (TEM)



John E. Bonevich, Wolfgang K. Haller


This assay protocol outlines procedures for sample preparation and the determination of mean nanoparticle size (in projection) using transmission electron microscopy (TEM). The projected diameter is the diameter of an equivalent hard uniform sphere supported on an electron-transparent substrate. Although the projected particle size is the primary determinant of the measured particle diameter, other parameters can impact these measurements and influence the measured size. Therefore, guidelines for making successful size measurements in the nanometer-size range are provided, as well as a discussion of relevant standards and data analysis. This protocol can be applied to any suitable TEM instrument with image recording capability. The specimen preparation protocol has been tailored for metallic nanoparticles possessing a negative charge in solution. This protocol is intended to be an evolving document; addenda that address material-class-specific sample preparation and analysis issues will be appended in the future.
Metallurgy Division of NIST


nanoparticle, transmission electron microscopy, particle size distribution


Bonevich, J. and Haller, W. (2010), Measuring the Size of Nanoparticles Using Transmission Electron Microscopy (TEM), Metallurgy Division of NIST, [online],, (Accessed June 17, 2024)


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Created March 1, 2010, Updated February 19, 2017