Field-based angle-resolved light-scattering study of single live cells

G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge,Massachusetts 02139, USA.
Optics Letters (Impact Factor: 3.29). 07/2008; 33(14):1596-8. DOI: 10.1364/OL.33.001596
Source: PubMed


We perform field-based angle-resolved light-scattering measurements from single live cells. We use a laser interferometer to acquire phase and amplitude images of cells at the image plane. The angular scattering spectrum is calculated from the Fourier transform of the field transmitted through the cells. A concurrent 3D refractive index distribution of the same cells is measured using tomographic phase microscopy. By measuring transient increases in light scattering by single cells during exposure to acetic acid, we correlate the scattering properties of single cells with their refractive index distributions and show that results are in good agreement with a model based on the Born approximation.

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    • "This approximation is often applied to biological cells [32] [57] [39] [40], interstellar dusts [35] [58] [59] and atmospheric aerosols [60] [61] [62]. In the case of biological cells [32] [33] [34], as in many other situations [35], it mainly produces errors on the energy scattered at large angles (i.e. a very small proportion of the total energy scattered by microorganisms), which explains the successful use of this approximation for the study of microorganisms' cross-sections in oceanography. In the following, we therefore consider that microorganisms are homogeneous and we define a single complex refractive index m "
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    • "Furthermore, it may account for differences caused by the time-dependent effect of acetic acid on tissue scattering and absorption. The vasoconstrictive and light scattering effects of acetic acid [35,36] may affect the extracted hemoglobin concentration, effective blood vessel radius, and also the scattering parameters. Recent work in our laboratory, which uses the same data set described in this paper, showed that without parameter normalization, HSIL sites could be differentiated from non-HSIL with AUC, sensitivity, and specificity of only 0.68, 78% and 67%, respectively [29]. "
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