Competitive Fluorescence

A competitive fluorescence-polarization immunoassay method was described for the monitoring of 12 drugs including valproic acid [18]. Samples (serum or plasma) were deproteinated. Fluorescence from the fluorescein-labeled analyte used as tracer was excited at 488 nm and polarization of light emitted at 531 nm was measured. The calibration was stable for 4 weeks and the coefficient of variation was below 10%. A single measurement took 8-10 min. 

An immunosensor based on a competitive fluorescence energy-transfer immunoassay was reported by Anderson 105) for the measurement of phenytoin. Texas red-labeled antibody was incubated with a phenytoin derivative. On displacement of the derivative by the antigen, the change in the fluorescence signal was recorded. Detection limits approached 5 /iM with response times ranging from 5 to 30 min. 

Triazine in solution DEAEM MIP-based competitive fluorescent assay 0.01 mM Piletsky et al., 1997... 

The immunoassay selected is based on a competitive fluorescence energy transfer mechanism. This type of assay is general and can be adapted to any antibody and antigen system. The competing reactions are given in equation (1) and (2) ... 

Kato, N., and Caruso, F. (2005). Homogeneous, competitive fluorescence quenching immunoassay based on gold nanoparticle/polyelectrolyte coated latex particles. J. Phys. Chem. B 109 19604-19612. 

Competitive Fluorescence. Antibodies to the antigen or hapten (analyte) are immobilized onto a solid support. Fluorophore-labeled and unlabeled antigen compete for a limited number of antibody binding sites. The support is rinsed and fluorescence is measured. Higher analyte concentrations result in fewer immobilized labeled species, yielding reduced fluorescence intensity. 

MbraPBPl could bind AMA. Since these initial studies, other probes have been tested and found to bind those PBPs that cannot bind AMA. 8-Anilino-l-naphthalene sulphonic acid (ANS) has been utilized in competitive fluorescence... 

Figure 4.13 Competitive fluorescence assay performed on arrays of 40-pun sized squares of PGMA structures grafted from ETFE. The samples were post-modified with biotin and incubated with fluorescently labeled strepta-vidin and biotin of increasing concentrations (0, 0.005. 0.05, 0.5, 5, and 50 pglmL). Relative fbtorescaux mtensi-ties were determined from fluorescence images shown as insets.

Cullum, M. E. Hine, R Simonson, L. G. Shih, C. N. Bienek, D. R. Park, S. Ragain, J. C. Rapid competitive fluorescence-polarization immunoassay of anthrax protective antigen in vaccine cultures and bodily fluids. U.S. Pat. Appl. Publ. US 2004235075, 2004 Chem. Abstr. 2004,142, 19550. 

Strengths The program is simple and quite straightforward to use. The 1 2 and competition fluorescence options... 

Rabon E, Sachs G, Bassilian S, et al. A K -competitive fluorescent inhibitor of the H,K-ATPase. J Biol Chem 1991 266 12395-12401. 

Atrazin Antibody marked with Eu complex Competitive fluorescence, fibre optics... 

TheophyUin Treated porous glass as filter/ theophylline marked with fluoresceine Competitive fluorescence, flow-through cell... 

IC50 measured in a competitive fluorescence polarization assay. 10 mM phosphate buffer (pH 7.4)... 

On a time scale of 10 -10 fs two more deactivation processes start to be competitive fluorescence emission (FE) and internal conversion (1C) [62]. The fluorescence emission is simply the radiative process associated with the emission of one photon and... 

FIGURE 68.15 Energy level diagram indicating the origins of the three competitive fluorescence transitions and two possible transient absorption transitions. The dashed level (Si ) represents a 90 twist between the planes of the donor and acceptor protons of structures 11 and III. 

---