Fluorescence polarization method

Intramolecular excimers have been used for probing bulk polymers, micelles, vesicles and biological membranes (Bokobza and Monnerie, 1986 Bokobza, 1990 Georgescauld et ak, 1980 Vauhkonen et al., 1990, Viriot et al., 1983 Zachariasse et ak, 1983). In particular, this method provides useful information on the local dynamics of polymer chains in the bulk (see Box 8.2). 

In conclusion, the method of intramolecular excimer formation is rapid and convenient, but the above discussion has shown that great care is needed for a reliable interpretation of the experimental results. In some cases it has been demonstrated that the results in terms of equivalent microviscosity are consistent with those obtained by the fluorescence polarization method (described in Section 8.5), but this is not a general rule. Nevertheless, the relative changes in fluidity and local dynamics upon an external perturbation are less dependent on the probe, and useful applications to the study of temperature or pressure effects have been reported. 

In Chapter 5, devoted to fluorescence polarization, it was shown that information on the rotational motions of a fluorophore can be obtained from emission anisotropy measurements. Application to the evaluation of the fluidity of a medium, or molecular mobility, is presented below. 

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Draw ratio X-ray method IR spectroscopy method Absorption Absorption band 898 band 1368 cm cm Optical method Fluorescent polarization method D R S D F method s... 

Polarized fluorescence arises from a different optical interaction with matter than does Raman scattering, but as in Raman scattering, the wavelength of the emitted light differs from that of the incident light. Also like Raman scattering, fluorescence polarization also allows one to measure both second and fourth moments of the orientation of specific bonds in a molecule. Monnerie (1987) has pioneered the application of fluorescence polarization methods to polymer dynamics. 

Maeda H, Nakayama M, Iwaoka D, Sato T. Assay of angiotensin I by fluorescence polarization method. Adv Exp Med Biol 1979 120A 203-11. 

For tests other than the Abbott fluorescence polarization method (which uses filtered fluid) and the lamellar body count, centrifuge the fluid for 2 minutes at 400 Xg. 

NBD-PC Fluorescence Polarization Method The NBD-PC method, also called FPol, is described in detail on the Evolve site that accompanies this book. The specimen is amniotic fluid that has been centrifuged at 400 Xg for 2 minutes. Results are expressed using artificial units of mil-lipolarization (P x 1000, mP). The analytical measurement range is 150 to 350 mP. No calibrators are used, but use of a Triton XlOO control assures that the temperature is correct and that the dye is not degraded. Comparison of the TDx FLM II and the NBD-PC assay reveals, as expected, a strong nonlinear, inverse correlation ... 

We discuss under this heading the use of fluorescence polarization methods to study the order In polymers, particularly In drawn fibrous materials and, by association, the use of such ordered systems to study fundamental details of the luminescence of probe molecules, the use of polarization methods to study rotational motion In polymers In solution, and the temperature dependence of luminescence as a probe of subgroup motion. 

Tanaka H, Yanagida T, Teramoto A, Fnjita H (1967) Studies of concentrated polymer solutions by fluorescence polarization method. I. Polyethylene oxide in water. J Phys Chem 71(8) 2416. doi 10.1021/j 100867a005... 

A fluorescence polarization method has been used to compare the association constants of the interactions between k- and osi-caseins and between lysozyme and ovalbumin. The latter interaction is electrostatic in nature. 

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