What is Perrin equation?

In steady state measurements, anisotropy follows the Perrin’s equation, r = r0/(1 + τRT/ηV), where r0 is the value of anisotropy at t = 0 after short pulse excitation, τ is the fluorescence life time of the fluorophore, η is the local viscosity of the solution, and V is the hydrodynamic radius, indicating the size and …

What does high fluorescence anisotropy mean?

Fluorescence anisotropy or fluorescence polarization is a measurement of the changing orientation of a molecule in space, with respect to the time between the absorption and emission events. IVH indicates the intensity when using a vertical polarizer on the excitation and horizontal polarizer on the emission.

What is the range of anisotropy values?

Anisotropy values can exceed 0.4 for multiphoton excitation (Chapter 18). where β is the angle between the absorption and emission transitions. The term r0 is used to refer to the anisotropy observed in the absence of other depolarizing processes such as rota- tional diffusion or energy transfer.

What is anisotropy decay?

The anisotropy decay, r(t), is related to the decays collected at emission polarizer angles of 0° and 90°, or vertical and horizontal, which are represented by IV(t) and IH(t), respectively, according to: (2) (3) The anisotropy decay of a sample consists of the anisotropy decay of each emitting species, ri(t).

What is anisotropy ratio?

The Zener ratio is a dimensionless number that is used to quantify the anisotropy for cubic crystals. It is sometimes referred as anisotropy ratio and is named after Clarence Zener. Conceptually, it quantifies how far a material is from being isotropic (where the value of 1 means an isotropic material).

What are anisotropics?

Anisotropic is the property of obtaining different values when observing or measuring something from different directions. The converse, isotropy, implies identical properties in all directions. Anisotropic properties of a material include its refractive index, tensile strength, absorbency, etc.

How is fluorescence detected?

Four essential elements of fluorescence detection systems can be identified from the preceding discussion: 1) an excitation light source (Figure 5), 2) a fluorophore, 3) wavelength filters to isolate emission photons from excitation photons (Figure 5), 4) a detector that registers emission photons and produces a …

What is anisotropy example?

anisotropic: Properties of a material depend on the direction; for example, wood. In a piece of wood, you can see lines going in one direction; this direction is referred to as “with the grain”. Strength is a property of the wood and this property depends on the direction; thus it is anisotropic.