Undergraduate Honors Thesis


Structural Brain Mapping Using Antibody-Conjugated Gold Nanoparticles and X-ray Microscopy Public Deposited

  • The current gold standard in cellular connectomics uses serial section electron microscopy approaches. But even when mapping very small regions of neural tissue (i.e. hundreds of micrometers), electron microscopy techniques can take months or years of work. Nondestructive methods which employ x-ray microscopy may facilitate far more efficient connectomic at resolutions sufficient for visualizing dendrites and axons. However, x-ray microscopy has so far been limited by chemical stains that cannot target desired tissue structures. A potential way of moving past this limitation is to use a gold nanoparticle contrast agent with covalently linked antibodies. To this end, an anti-dopamine 1 receptor antibody (anti-D1R) was conjugated to 60×27 nm gold nanorods. Immunohistochemical assays were performed on sections of rat striatum to verify the staining efficacy of these immunogold constructs. After an anti-Fab secondary antibody linked to Alexa Fluor® 488 was reacted with the primary antibodies on the gold nanorods, tissue fluorescence demonstrated that the immunogold had bound the striatum. X-ray microscopy was performed using a ZEISS Xradia 520 Versa x-ray microscope on a region of striatum that had been treated with the immunogold contrast agent. With a scan time of just 13h, the resulting three-dimensional reconstruction revealed neurites at a 386 nm pixel size. Next, a thick tissue volume was treated using 5 nm spherical gold nanoparticles with covalently linked anti-D1R antibodies. This volume was then imaged via x-ray microscopy at a pixel size of 403 nm and with a scan time of 16h. Some neurites were visible in the reconstruction, but the high concentration of nanoparticles may have obscured many of the finer features. The proof-of-concept data acquired from rat striatum demonstrate this approach’s promise for high-throughput imaging of neuronal tissue.
Date Awarded
  • 2019-01-01
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Last Modified
  • 2020-01-06
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