Related Experiment Video
Updated: Mar 12, 2026
09:56
Direct Force Measurements of Subcellular Mechanics in Confinement using Optical Tweezers
Published on: August 31, 2021
5.8K
Quantifying Force and Viscoelasticity Inside Living Cells Using an Active-Passive Calibrated Optical Trap.
Christine M Ritter1, Josep Mas2, Lene Oddershede1
1Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark.
Methods in Molecular Biology (Clifton, N.J.)
|November 16, 2016
Summary
Optical tweezers enable precise in vivo force measurements within living cells. This new method calibrates the optical trap without needing to know the trapped object or cell properties.
Area of Science:
- Biophysics
- Cell Biology
- Single-molecule manipulation
Background:
- Optical tweezers are precise tools for in vitro single-molecule studies in controlled environments.
- In vivo applications of optical tweezers are limited for quantitative force measurements due to unknown trap spring constants in cellular cytoplasm.
Purpose of the Study:
- To describe a novel method for quantitative in vivo force measurements using optical tweezers.
- To overcome the challenge of unknown optical trap spring constants within living cells.
Main Methods:
- Utilizing optical tweezers for quantitative in vivo force measurements.
- Employing two experimental approaches: passive observation of thermal motion and response to controlled trap oscillations.
- Developing a data analysis protocol for accurate force measurements.
Main Results:
- A method for calibrating optical tweezers in vivo without prior knowledge of trapped object size, refractive properties, or cellular viscoelasticity.
- Demonstration of the protocol using trapped granules within live S. pombe cells.
Conclusions:
- This method enables precise quantitative force measurements in vivo using optical tweezers.
- The technique simplifies in vivo single-molecule force experiments by removing the need for environmental or object property characterization.
