Fluorescence polarization techniques

The fluorescence polarization technique is a very powerful tool for studying the fluidity and orientational order of organized assemblies (see Chapter 8) aqueous micelles, reverse micelles and microemulsions, lipid bilayers, synthetic non-ionic vesicles, liquid crystals. This technique is also very useful for probing the segmental mobility of polymers and antibody molecules. Information on the orientation of chains in solid polymers can also be obtained. 

The choice of method depends on the system to be investigated. The methods of intermolecular quenching and intermolecular excimer formation are not recommended for probing fluidity of microheterogeneous media because of possible perturbation of the translational diffusion process. The methods of intramolecular excimer formation and molecular rotors are convenient and rapid, but the time-resolved fluorescence polarization technique provides much more detailed information, including the order of an anisotropic medium. 

Other successful homogeneous assays have been developed such as the fluorescence polarization technique made available by Abbott Laboratories of North Chicago, USA. This competitive immunoassay technique relies upon the principle... 

Nl. Nakajima, K., Mochida, H., Ueno, T., Suzuki, M., Kobayashi, I., Matsuda, I., and Miyai, K., A simple, rapid method of blood thyroxine assay using a fluorescence polarization technique. Proc. Symp. Chem. Physiol. Pathol. Annu. Meet. Jpn. Soc. Clin. Chem. 18, 30-35 (1978). 

Alfonso, C., Alfonso, A., Vieytes, M.R., Yasumoto, T, and Botana, L.M. 2005. Quantification of yessotoxin usingthe fluorescence polarization technique and study of the adequate extraction procedure. Anal Biochem 344,266-274. 

Fluorescence polarization techniques and ordered molecular systems... 

The effect of various environmental factors, such as the pH, the ionic strength, and the composition of solvent on the association kinetics has also been studied using the fluorescence polarization technique. 

As a preliminary, the recently proposed theory of segmental orientation of real networks with constraints on junctions is reviewed. Basic principles of fluorescence polarization technique and its application to investigation of molecular orientation of mobile, anisotropic networks are then described. Illustrative data on elasticity and orientation behaviors of cis-polyisoprene networks are consistent with theoretical predictions. 

Recent developments in spectroscopic techniques allow for accurate measurement of orientations of structural units in deformed polymeric systems Infrared dichroismCI-R-D) H - N-M.R. spectroscopy, fluorescence polarization (F.P.) are three methods which find increasing use in experimental investigations- The experiments reported in the present paper concern effectively simultaneous measurements of orientation by fluorescence polarization and of stress-strain relationship. It is worth noting that the transition moments of the label involved in fluorescence polarization are not sensitive to their immediate environment. Previous models are briefly reviewed and a new model of orientation of real networks is proposed- Then the fluorescence polarization technique is described and theoretical predictions are compared with measurements on polyisoprene vulcaniza-tes. 

The fluorescence polarization technique may be applied successfully to these cases as shown by the recent work of Laurence (1952) on the adsorption of dyes on serum albumin. 

Fluorescence polarization techniques have proved to be a very useful method of investigating the environment and motion of fluorescent molecules and fluor-ophores within larger macromolecules. 

THE FLUORESCENCE POLARIZATION TECHNIQUE AS A TOOL TO INVESTIGATE CHAIN ORIENTATION AND RELAXATION IN BULK POLYMERS... 

After presenting the fluorescence polarization technique, we will consider its application to bulk polystyrene stretched above its glass transition temperature, looking at the influence of the molecular weight of the matrix or of the labelled chain. 

Before considering the fluorescence polarization technique which leads to a measurement of the orientation distribution of characteristic vectors, we introduce some convenient quantities to describe the orientation of uniaxially symmetric systems. 

In the fluorescence polarization technique, the intrinsic optical constants (6(33 —flii)/ o ( 33 11)1 0 can be determined. With random orientation, one can obtain (X2 using equation (63), where the value of 2 varies from zero to unity depending on the absorption and emission anisotropies of the chromophoric group. Alternatively, one can obtain the material constant aj independently of the degree of orientation given by equation (64). Then the intrinsic optical constants of absorption and emission anisotropies can be determined by equations (65). Finally, one can calculate the moments of from the linear combination of Ly and the intrinsic optical constants. As a result, the... 

Huchzermeier, R. E Spring, T. G. Determination of unsaturated thyroxine binding protein sites using fluorescence polarization techniques. Eur. Pat. Appl. EP 0108400,1984. 

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