Direct Synthesis of EM-Visible Gold Nanoparticles in Cells for Protein Localization Analysis with Well-Preserved Ultrastructure

Zhaodi Jiang

doi:10.3791/65246

/

Direct Synthesis of EM-Visible Gold Nanoparticles in Cells for Protein Localization Analysis with Well-Preserved Ultrastructure

JoVE Journal
Biology

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JoVE Journal Biology

Direct Synthesis of EM-Visible Gold Nanoparticles in Cells for Protein Localization Analysis with Well-Preserved Ultrastructure

1,281 Views

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09:22 min

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April 28, 2023

DOI:

10.3791/65246-v

DOI:

10.3791/65246-v

•

09:22 min

April 28, 2023

•

5 Views

Zhaodi Jiang^1,2

¹National Institute of Biological Sciences, Beijing, ²Tsinghua Institute of Multidisciplinary Biomedical Research,Tsinghua University

Transcript

Protein detection and localization are essential in biological research. Our protocol describes a novel EM-labeling technology using genetically-encoded tags which allows single-molecule visualization in situ with well-preserved ultrastructure. It is crucial to avoid over-fixation.

The labeling method is based on the activity of cysteines in the tags, which are highly sensitive to aldehyde cross-linking. Our protocol avoids use of aldehyde fixatives and preserves the tag activity and ultrastructure. at the same time.

EM labeling has always been challenging, suffering from poor morphology or inefficient labeling. Our protocols synthesizes in situ nanoparticles directly on individual proteins to provide clear and precise localization of the target proteins, with a high signal-to-noise ratio, high efficiency, and specificity. We have so far achieved excellent labeling in isolated proteins, E.coli cells, yeast cells, and HeLa cells.

We will explore and optimize the method for application to tissue samples. Combining the prevailing cryo-FIB and cryo-EM technologies will allow us to address important biological questions.

Summary

The present protocol describes a clonable electron microscopy labeling technology for detecting metallothionein-tagged proteins in cells using a novel autonucleation suppression mechanism-based gold nanoparticle synthesis technique.