Angle-resolved light scattering of individual rod-shaped bacteria based on Fourier transform light scattering

Abstract

Two-dimensional angle-resolved light scattering maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform light scattering techniques, the light scattering patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from −70° to 70°. The measured light scattering patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic light scattering. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in light scattering within bacterial species is related to the cellular dry mass and growth.

Measurements of morphological and biophysical alterations in individual neuron cells associated with early neurotoxic effects in Parkinson's disease

“…Based on the principle of holography, QPI techniques exploits the refractive index (RI) distribution of optical contrasts to provide quantitative and label-free images of live cells and tissues. QPI techniques have been applied to study the pathophysiology of various biological samples, including hematology (10), malaria infection (11,12), sickle cell diseases (13)(14)(15)(16), and microbiology (17,18). In particular, 2D QPI techniques or digital holographic microscopy techniques had been utilized for the study of biophysics of neuron cells (19,20) and for imaging alterations in brain tissue slices caused by Alzheimer's disease (21).…”

Three-dimensional label-free observation of individual bacteria upon antibiotic treatment using optical diffraction tomography

“…Previously, 2D QPI techniques have been applied for the study of individual bacteria [54], [55,56]. However, 2D QPI only measures the optical phase delay maps, an integration of RI values along an optical path, and does not provide tomographic measurements of individual bacteria.…”

High-Resolution 3-D Refractive Index Tomography and 2-D Synthetic Aperture Imaging of Live Phytoplankton

“…(2) Even though the particular focus of this study is on static 3-D images of phytoplankton, dynamics of 3-D RI tomograms of individual phytoplankton can allow to measure intracellular dynamics of subcellular organelles [39][40][41] or dynamics fluctuation in cell membrane [42][43][44][45][46][47] which can provide abundant information about pathophysiology of phytoplankton. (3) In addition, recent advances in QPI techniques can also be further employed to investigate phytoplankton research including super-resolution imaging [48], Fourier transform light scattering technique [49][50][51][52][53], real-time visualization of 3-D RI maps [54], multi-spectral QPI [55][56][57][58][59], and polarization-sensitive QPI [60,61]. (4) Furthermore, QPI techniques can be accessible to an existing microscope by attaching the recently developed QPI unit [62,63], which will further extend the applicability of QPI techniques for the study of phytoplankton.…”