Rhodamine derivatives

The following sections describe the most important rhodamine derivatives commonly used to label biomolecules. 

The fluorescent probe, 5-(((2-(carbohydrazino)methyl)thio)acetyl)-aminofluorescein, is soluble in DMF or in buffered aqueous solutions at pH values above 7.0. The reagent may be dissolved in DMF as a concentrated stock solution before adding a small aliquot to an aqueous reaction medium. The compound itself and all solutions made with it should be protected from light to avoid decomposition of its fluorescent properties. 

The methods for using this reagent in labeling glycoproteins on cell surfaces or in solution are similar to those described for fluorescein-5-thiosemicarbazide, above. 

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Beija M, Afonso CAM, Martinho JMG (2009) Synthesis and applications of Rhodamine derivatives as fluorescent probes. Chem Soc Rev 38 2410-2433... 

Figure 9.13 The primary rhodamine derivatives useful for fluorescent labeling.

Aldehyde/Ketone and Cytosine-Reactive Rhodamine Derivatives... 

Cu2+ and Hg2+ are perhaps the most obvious targets for reaction-based signaling systems. However, this approach has also been realized for monovalent Ag+. Here, again a rhodamine derivative (rhodamine B spirolactam 48, Fig. 18) allows the highly selective detection of Ag+ with a detection limit of 14 ppb in water containing 20% ethanol. Silver nanoparticles, a topical analyte today, can also be detected, after oxidation of the particles with H2O2/H3PO4 [141]. The selectivity was tested with Ca2+, Ba2+, Mg2+, Cr2+, Mn2+, Fe3+, Co2+, Ni2+, Cu+, Cu2+, Zn2+, Pd2+, Cd2+, Hg+, and Hg2+ and no interference was found. 

Rhodamine derivatives are widely used as laser dyes, and intramolecular rotational motion of a dialkylamino group leading to a nonemissive TICT state has been... 

The red-emitting rhodamine derivatives are constructed around the same basic xanthene framework as is fluorescein (2). Tetramethylrhodamine isothiocyanate (TRITC) has been widely employed for immunofluorescence. Additional derivatives of rhodamine available for conjugation to antibodies include lissamine rhodamine sulfonyl chloride (RB-200-SC), rhodamine B isothiocyanate (RBITC), rhodamine X isothiocyanate (XRITC), and Texas... 

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