Darkfield Microscopy to Visualize Diffusional Dynamics of Nanorods on Cell Membrane

Published: July 31, 2023

Abstract

Source: Ge, F., et al. Visualizing Diffusional Dynamics of Gold Nanorods on Cell Membrane using Single Nanoparticle Darkfield Microscopy. J. Vis. Exp. (2021).

In this video, we describe the darkfield microscopy (DFM) technique combined with single-particle tracking (SPT) analysis to monitor the interaction of plasmonic gold nanorods with the cell membrane of a specific cell line of interest. Combined DFM and SPT analysis allows the visualization of the nanorod movement through the cell membrane with high spatiotemporal resolution.

Protocol

1. Microscope slide preparation NOTE: U87 MG cells of the third to tenth generation with high activity are used in SPT experiments. Sterilize 22 mm × 22 mm coverslips already cleaned with Piranha solution by immersing in ethanol (99.9%). Use forceps to take out the cover slip from the ethanol solution (step 1.1) and sterilize by burning ethanol on the flame. Once all ethanol is burnt, place coverslips in a plastic cell culture dish (…

Representative Results

Figure 1: Schematic diagram of the optical path of darkfield microscopy, microscope slide preparation, and the dual-channel difference method for calculating polar angle (θ) of AuNRs. Scale bar in image is 2 μm. Figure 2: Characterization of CTAB-AuNRs. (A) TEM images of CTAB@AuNRs….

Disclosures

The authors have nothing to disclose.

Materials

CTAB-coated gold nanorods (CTAB-AuNRs) Nanoseedz NR-40-650 85 nm*40 nm
Color CMOS camera Olympus DP74 Japan
Coverslips Citoglas z10212222C 22*22 mm
Dark-field microscopy Nikon 80i Upright microscope
Fetal bovine serum (FBS) Gibco 10099141
Fiji National Institutes of Health 2.0.0-rc-69/1.52 p A distribution of ImageJ
Grooved glass slide Sail brand 7103 Single concave
Image J Image J 1.52 j
MATLAB MathWorks R2019b
MATLAB Code https://github.com/fenggeqd/ JOVE-2020
Plastic cell culture dishes Falcon 353002
Plastic cell culture dishes Falcon 353001 35*10 mm
U87 MG cell American Type Culture Collection ATCC HTB-14 A human primary glioblastoma cell line
Minimum essential medium (MEM)  Gibco  51200038 No phenol red
Penicillin-streptomycin  Gibco  15140122

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Cite This Article
Darkfield Microscopy to Visualize Diffusional Dynamics of Nanorods on Cell Membrane. J. Vis. Exp. (Pending Publication), e21458, doi: (2023).

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