Speaker
Description
Advancements in interferometric scattering microscopy (iSCAT) enable label-free detection of nanoscale structures and dynamics with high sensitivity and fast acquisition rates. This technology overcomes fluorescence imaging limitations, such as photobleaching, facilitating long-term or high-speed measurements. However, analyzing label-free signals to extract specific target information remains challenging. In this work, we employ coherent bright field microscopy (COBRI), an iSCAT microscope in transmission mode, to capture chromatin scattering signals in live cell nuclei at 5000 frames per second. Utilizing back pupil function engineering and a high numerical aperture microscope condenser enhances detection of weak chromatin signals and optical sectioning. Through correlation spectroscopy analysis, we spatially estimate the diffusion coefficient, density, and condensation state of chromatin, specifically. Taken together, we introduce interferometric scattering correlation spectroscopy (iSCORS) to spatially measure nanoscopic chromatin dynamics. Using iSCORS imaging, we successfully observe spontaneous fluctuations in chromatin condensation and chromatin condensation dynamics in response to transcription inhibition. Detailed image processing and temporal analysis will be discussed.
