From Beams to Biomolecules: Calibrating and Constructing an IR Optical Tweezer for Shark Muscle Analysis

Optical tweezers are a Nobel Prize-winning technology that traps microscopic and submicroscopic particles with a laser beam. The tweezers rely on radiation pressure from the beam, focused by a microscope objective, and can apply forces to measure displacements in the nanometer range. While optical tweezing has been used to study a variety of biomolecules, we aim to adapt this technology to study the locomotor muscles of sharks, potentially applying the technology to other marine life taxa. Some studies use optical tweezing to study biomolecules of other fishes, but it is an underexplored field. Our goal is to isolate titin—a protein found in muscle fibers that contributes to their passive elasticity—to better understand the elasticity of sarcomeres in shark swimming muscles. This project involves the construction and calibration of the optical tweezing setup, including aligning the IR (infrared laser), optimizing data acquisition, and developing research skills related to the construction of the research setup. We work in tandem with marine research students that are developing methods for accurate titin isolation from white muscle in various shark species to understand the ecological implications of our findings. This is part of the broader goal of developing interdisciplinary research collaboration with high school students.