Title

Superb Resolution And Contrast Of Transmission Electron Microscopy Images Of Unstained Biological Samples On Graphene-Coated Grids

Keywords

Electron microscopy; Mass per length; Molecular structure; Prion

Abstract

Background In standard transmission electron microscopy (TEM), biological samples are supported on carbon films of nanometer thickness. Due to the similar electron scattering of protein samples and graphite supports, high quality images with structural details are obtained primarily by staining with heavy metals. Methods Single-layered graphene is used to support the protein self-assemblies of different molecular weights for qualitative and quantitative characterizations. Results We show unprecedented high resolution and contrast images of unstained samples on graphene on a low-end TEM. We show for the first time that the resolution and contrast of TEM images of unstained biological samples with high packing density in their native states supported on graphene can be comparable or superior to uranyl acetate-stained TEM images. Conclusion Our results demonstrate a novel technique for TEM structural characterization to circumvent the potential artifacts caused by staining agents without sacrificing image resolution or contrast, and eliminate the need for toxic metals. Moreover, this technique better preserves sample integrity for quantitative characterization by dark-field imaging with reduced beam damage. General significance This technique can be an effective alternative for bright-field qualitative characterization of biological samples with high packing density and those not amenable to the standard negative staining technique, in addition to providing high quality dark-field unstained images at reduced radiation damage to determine quantitative structural information of biological samples.

Publication Date

6-1-2013

Publication Title

Biochimica et Biophysica Acta - General Subjects

Volume

1830

Issue

6

Number of Pages

3807-3815

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.bbagen.2013.03.002

Socpus ID

84876195465 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84876195465

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