Related Experiment Video
Updated: Aug 6, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Orientational order parameter of the nematic liquid crystalline phase of F-actin
Jorge Viamontes1, Suresh Narayanan, Alec R Sandy
1Department of Physics, Brown University, Providence, Rhode Island 02912, USA.
Abstract:
We measured the orientational order parameter of F-actin traversing the isotropic-nematic phase transition using a combination of techniques, including fluorescence imaging, local birefringence measurements, and small-angle x-ray scattering. The order parameter approaches a saturated value of 0.75 for actin concentrations above the region of the isotropic-nematic phase transition. This result implies a significant extent of misalignment and consequently entanglement among long actin filaments, even in the nematic phase. We determine the specific birefringence of completely aligned F-actin to be Deltan(0)=2.3 x 10(-5) ml/mg. At concentrations slightly below the isotropic-nematic transition, nonzero values of the order parameter are detected for hours following an initial alignment, indicating extremely slow rotational kinetics of F-actin in the entangled networks.
More Related Videos
06:24High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
06:48Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
Published on: July 11, 2025
Related Concept Videos
Polarity of the Cytoskeleton
Formation of Higher-order Actin Filaments
The high-order actin networks...
Properties of Enantiomers and Optical Activity
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Generation of Straight or Branched Actin Filaments
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Actin Polymerization
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight actin...