Ratiometric analysis

Ratiometric analysis, 200, 20If Red cells. See erythrocytes Red diode laser, 63, 64t Refractive index, 6, 27-28, 65, 155 Region, 253... 

D. WUhams, S. Chen, M.K. Young, Ratiometric analysis of the ferrocene boronate esters of 2-and 4-hydroxyestradiol by ESI-MS-MS, Rapid Commun. Mass Spectrom., 15(2001)182. 

Figure 6.32 (a) Ratiometric analysis of glucose 20 min (c) Quenched fluorescence ofthe COx-... 

Ying, LM, Wallace, MI, Balasubramanian, S, and Klenerman, D, Ratiometric analysis of single-molecule fluorescence resonance energy transfer using logical combinations of threshold criteria A study of 12-Mer DNA. Journal of Physical Chemistry B 104 (2000) 5171-5178. 

Two-dye MBs contain two fluorophores at different ends of the MB. This produces a different fluorescence output in the presence and absence of the target due to FRET. Ratiometric analysis can be used in these kinds of MBs to improve the S/B ratio 14, 24). 

Yu and Parker prepared cyclen derivatives 58 and 59 bearing a pyri-dothioxanthone for the photosensitization of luminescent Eu cation, which provided a 6- (N4O2) and a 7-coordination (N5O2) mode [139]. Addition of malate anion to a solution of Eu +-58 increased the intensity of the A/= 2 bands, but decreased that of A/= 0 transition. Eu -59 exhibited a pronounced sensitivity for citrate anion [140]. Therefore, these were apph-cable in the ratiometric analysis or imaging of the aforementioned anions. 

FIGURE 6.13 Example of selected graphical output for ratiometric assay analysis. 

Figure 6.15 Applying dual-color ratiometric gene expression labeling approach to protein expression analysis. (From Haab, B.B. etal., Genome Biol., 2, 0004.1-0004.13, 2001. With permission.)...

Macrocyclic 25 has been constructed with pseudocryptand 26 which can be discerned within Tsien s ratiometric fluorescent sensors as the Na receptor unit. Conformational changes by 26 upon ion binding allows strong off-on PET sensing action due to the ion-induced increase of its oxidation potential. X-ray structural evidence for the Na -induced conformational changes in 26 shows decreased conjugation with a 40° twist about the C-N bond of the 2-anisidine unit. X-ray evidence is also available for similar conformational changes in the non-macro-cyclic Ca " receptor 23. A related analysis has been made for a Ag" -phenyl-azacrown ether interaction which involves a soft-soft component. ... 

Since the heterocyclic-substituted platinum 1,2-enedithiolates are dual emitters with only one emission that is oxygen quenched, ratiometric oxygen analysis is possible (see Fig. 3) (21, 29). While fluorescence and phosphorescence intensities vary with changes in optical clarity, fluctuations in the source and detector, and photobleaching of the emitter, the intensity ratio of a dual emitter (phosphorescence-fluorescence) does not. As such, the 3I/1I intensity ratio can be used in place of I, in Eq. 3 to generate Eq. 7 and 8 (29-31, 69). 

Bretonniere, Y, Cann, M.J., Barker, D., and Slater, R. (2002) Ratiometric probes for hydrogencarbonate analysis in intracellular or extracellular environments using europium luminescence. Chemical Communications, 1930-1931. 

Pilohello KT, Slawek DE, Mahal LK. A ratiometric lectin mi- 107. croarray approach to analysis of the dynamic mammalian gly-... 

Many of these dyes and their applications have been reviewed in detail elsewhere (50). Of note, probes are available for both UV and 488 nm excitation and many of these calcium probes (Fura-l, Indo-1, Calcium Green-2) have the advantage of utilizing a ratiometric fluorescence read-out. These dyes have been successfully used in multiparametric analyses, using both flow cytometry and confocal microscopy, which has led to an enhanced understanding of the role of [Ca2+]i in apoptosis. Burchiel et al. (51) have recently published a review of multiparametric flow cytometric Ca2+ analysis. 

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