Manipulation of Jurkat T-Cell Membrane Tethers with NanoTracker 2 Optical Tweezers

^{KEYWORDS: Optical Tweezers; NanoTracker; Jurkat T-Cell Membrane; Tether Formation; Force Spectroscopy; Cell Biology; Life Sciences}

Light photons have both linear and angular momentum. This fundamental property plays a key role in the physical phenomenon of optically trapping objects with a highly focused laser beam. The Optical Tweezers (OT) technique utilizes this property of light and allows the direct trapping and manipulation of objects on the scale of several tens of nanometers up to tens of micrometers. Furthermore, OT enable non-invasive, nanometer-precise manipulation of biological samples both in vitro and in vivo, while simultaneously applying and recording the piconewton forces acting on the measured systems. The last two decades have seen OT develop from a proof-of-principle experiment to an essential quantitative force spectroscopy method for the analysis of biological samples ranging from single molecules to complex processes, and interactions in living cells.

In this app note, we have successfully used the latest generation NanoTracker 2 optical tweezers to study the mechanical properties of Jurkat T-cells. It was demonstrated that the instrument can be used in membrane tether pulling experiments on living cells while, non-invasively, measuring the tether formation force and plateau force with a high resolution and reproducibility. The cellular mechanical properties obtained this way vary for different type of cells. Membrane tension can fluctuate in different regions of the same cell, in moving cells, and because of differences in the composition of the plasma membrane and the surface of the substrate.

Readers can expect to learn about:

• The basics of cell membrane properties and tether formation;
• Membrane tether experiments and force spectroscopy of living cells in the pN range with the NanoTracker Optical Tweezers system; and
• The benefits and the potential of the Optical Tweezers technology for investigating mechanical properties of living cells such as Jurkat T-cells.