31
FluoroMax
®
-4 & FluoroMax
®
-4P with USB v. B (23 Oct 2009)
Automated Polarizers
10-13
Using automated polarizers
FluorEssence™ software with HORIBA Scientific polarizers provides many choices
for polarization measurements. Depending on the accessories, the opportunity exists to
remove polarization effects from the sample, measure the polarization characteristics,
or analyze the decay of anisotropy using frequency-domain techniques. For further
software information, refer to the FluorEssence™ and Origin
®
on-line help.
Applications for polarizers
• Measurement of emission anisotropy or polarization at fixed wavelengths. This is
used for binding assays, kinetics of molecular size- or shape-change, temperature
effects on rotational motion of fluorophores (e.g., phase transition of phospholipid
bilayers).
• Measurement of excitation and emission spectra using magic angles. This helps to
eliminate spectral artifacts.
• Measurement of a principal polarization or excitation anisotropy spectrum, using an
excitation scan with polarization. This provides information about rotational sensi-
tivity of the excitation spectrum by measuring 〈r〉 versus λ
exc
(with λ
em
constant).
Examine relative molecular dipole-angles at cryogenic temperatures in a viscous
solvent.
