Title: Single-Molecule Optical Imaging with Improved Spatial Resolution and Chiral Fingerprinting for Disease biology
Student Name: Mr. Aravinth S
Date/Time: 17.04.2026 / 11:30 AM
Research Supervisor : Partha P Mondal
Venue: S V Narsaiah Auditorium, IAP Department.
Abstract:
Single-molecule localization microscopy surpasses the classical diffraction limit by recording temporally separated stochastic events (single-molecule PSFs). The data is then processed to construct the super-resolved map of subcellular structures. This thesis addresses three significant advances in the field of Single Molecule Localization Microscopy: (1) time correlation invoked spatial resolution improvement (~2-fold), (2) investigates the chiral nature of single molecules, and (3) their applications in disease biology. The first aspect of the work presents a technique to enhance localization precision by identifying molecules that emit photons over an extended temporal window. By correlating the point spread functions of these molecules across frames, we can leverage cumulative photon counts to achieve high localization precision, which directly relates to spatial resolution. The developed technique is tested on three different photoactivatable fluorescent proteins (Dendra2-Actin, Dendra2-Tubulin and mEos-Tom20) on NIH3T3 cells, showing two-fold improvement in localization precision. The second work presents a new SMLM technique (chiralSMLM) to explore single-molecule chirality. This involves the detection of right and left circularly polarized fluorescence from single molecules, followed by the calculation of the degree of chiral dissymmetry factor, which becomes the basis for generating a chiral fingerprint map of single molecules. The final and third part elaborates on the use of these techniques for understanding the role of viral proteins (conjugate molecules) in infected/transfected cells (disease models: Influenza and Dengue) which indicate left-handed molecule have a dominant role in clustering as compared to right-handed molecules. These developments bridge the gap between advanced optical imaging and molecular biology with a special emphasis on disease biology.