Title: Lightsheet optical tweezer – a powerful tool for 2D trapping and imaging of live cell & multicellular organisms
Student Name: Mr. Neptune Baro
Date/Time: 10.04.2026 / 11:30 AM
Research Supervisor: Partha P Mondal
Venue: S V Narsaiah Auditorium, IAP Department.
Abstract:
Since its inception, optical tweezers have become tools for manipulating microscopic specimens in biology, physics, and biotechnology. They have undergone significant advancements in recent years. We present the first lightsheet optical tweezer system, which can be used for line traps (LOT system), 2D traps (pLOT system), and adaptive trapping that switch between point and line traps(TRIMMing system). This lightsheet-based trapping modality can simultaneously trap and image live specimens with high resolution in near-native environments. The developed system is realized using a combination of a cylindrical lens and a high-NA objective lens. Unlike conventional point-based optical tweezers, this system can trap multiple particles and live cells in a line and a 2D plane using a tightly focused, diffraction-limited light sheet. As a testament to the proposed system’s ability for line traps, we successfully trapped dielectric silica beads and HeLa cells in a line. Later, the trapped cells were arranged to form many different patterns, demonstrating the tool’s potential for cell patterning. Furthermore, the system was successfully employed to trap and fluorescently image beads (silica, polystyrene) and live cells (HEK, HeLa, NIH3T3) within a defined 2D plane. To overcome limitations associated with static single trapping geometries and to enable immobilization-free interrogation, we further developed a TRIMing (TRapping and IMaging) technique based on an adaptive light-sheet optical tweezer system. This system integrates an electrically tunable lens (ETL), cylindrical lens, and objective lens to dynamically change the beam profile and generate either point or sheet PSFs. Live HeLa cells and Caenorhabditis elegans are effectively trapped and imaged in freely moving environments. The lightsheet optical tweezer system enables studies of biophysical parameters, such as size, density, and distributions of organelles, including lipid droplets, indicating distinct physiological states across specimens. Overall, these advances open new horizons for deciphering cellular processes, patterned cell growth, and constrained particle dynamics.