Subcellular Nanoparticle Distribution from Light Transmission Spectroscopy

We have measured the particle-size distribution (PSD) of subcellular structures in plant and animal cells. We have employed a new technique developed by our group, Light Transmission Spectroscopy---combined with cell fractionation---to accurately measure PSDs over a wide size range: from \textasciitilde 10 nm to 3000nm, which includes objects from the size of individual proteins to organelles. To date our experiments have included cultured human oral cells and spinach cells. These results show a power-law dependence of particle density with particle diameter, implying a universality of the packing distribution. We discuss modeling the cell as a self-similar (fractal) body comprised of spheres on all size scales. This goal of this work is to obtain a better understanding of the fundamental nature of particle packing within cells in order to enrich our knowledge of the structure, function, and interactions of sub-cellular nanostructures across cell types.