Direct And Highly Sensitive Measurement Of The Spatial Arrangement Of Micro-Structures Within Biological Samples

Quantitative morphological assessment of biological cells and their subcellular environment is important to characterize cellular state in normal and diseased tissue and cellular response to various experimental treatments. Recently, we showed that optical Gabor-like filtering of light scattered by spheres yields an optical measurement which varies linearly with diameter. In addition, the sensitivity to changes in size was superior to post-processing of digital images. Here, we extend our previous results by showing that the linear relationship between Gabor filter period and particle size holds over a size range from 100nm to 2000nm. We also show that this relationship is independent of the particle's or medium's refractive index. Using simulations, we provide a theoretical basis for our findings. Unlike previous methods, this technique does not require the presence of single isolated particles and thus may be used to directly extract the characteristic size associated with the local texture of heterogeneous objects. We therefore discuss this applicability of our method in heterogeneous samples consisting of collagen and living cells.