Flow birefringence

In biochemistry, flow birefringence is a hydrodynamic technique for measuring the rotational diffusion constants (or, equivalently, the rotational drag coefficients). The birefringence of a solution sandwiched between two concentric cylinders is measured as a function of the difference in rotational speed between the inner and outer cylinders. The flow tends to orient an ellipsoidal particle (typically, a protein, virus, etc.) in one direction, whereas rotational diffusion (tumbling) causes the molecule to become disoriented. The equilibrium between these two processes as a function of the flow provides a measure of the axial ratio of the ellipsoidal particle.

Protein structural analysis

High resolution	Cryo-electron microscopy X-ray crystallography NMR Electron crystallography EPR

Medium resolution	Fiber diffraction Mass spectrometry SAXS

Spectroscopic	NMR Circular dichroism Dual Polarisation Interferometry Absorbance Fluorescence Fluorescence anisotropy

Translational Diffusion	Analytical ultracentrifugation Size exclusion chromatography Light scattering NMR

Rotational Diffusion	Fluorescence anisotropy Flow birefringence Dielectric relaxation NMR

Chemical	Hydrogen-deuterium exchange Site-directed mutagenesis Chemical modification

Thermodynamic	Equilibrium unfolding

Computational	Protein structure prediction Molecular docking

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Flow birefringence

See also