Texas Red structure

Finally, another group of derivatives are the aldehyde-/ketone-reactive probes. This group is based on the activation of a sulfonyl hydrazine group of carbon number 5. They are based on Lissamine and Texas Red structures and used to label aldehyde-/ketone-containing molecules (with sugars). The most common aldehyde-/ ketone-reactive probes are Lissamine rhodamine B hydrazine and Texas Red hydrazine. 

Four forms of amine-reactive rhodamine probes are commonly available. Two of them are based on the tetramethyl derivatives of the fundamental rhodamine structure, one is based on the sulforhodamine B or Lissamine derivative, and the last is the sulforhodamine 101 or Texas Red-type of derivative. All of them react under alkaline conditions with primary amines in proteins and other molecules to form stable, highly fluorescent complexes. 

Texas Red hydrazide is a derivative of Texas Red sulfonyl chloride made by reaction with hydrazine (Invitrogen). The result is a sulfonyl hydrazine group on the No. 5 carbon position of the lower-ring structure of sulforhodamine 101. The intense Texas Red fluorophore has a QY that is inherently higher than either the tetramethylrhodamine or Lissamine rhodamine B derivatives of the basic rhodamine molecule. Texas Red s luminescence is shifted maximally into the red region of the spectrum, and its emission peak only minimally overlaps with that of fluorescein. This makes derivatives of this fluorescent probe among the best choices of labels for use in double-staining techniques. 

Figure 5 (a) The structure of T4 lysozyme with the two dye labels schematically shown, (b) Fluorescence intensity trajectories of the TM R donor (blue) and the Texas Red acceptor (red) of a single T4 lysozyme in the presence of E coli B cell wall, (c) Distribution of the decay rate constants (/t) of the donor intensity autocorrelation functions. Reproduced with permission from Y. Chen D. Hu E. R. Vorpagel H. P. Lu, J. Phys. Chem. B. 2003,107, 7947-7956. Copyright (2003) American... 

Fiber scaffolds containing fibers of two unique compositions were obtained using the DS electrospinning apparatus. Macroscopically, the scaffold was a conformable and resilient structure having ultraflne cloth appearance. Fluorescence microscopy of the scaffold, which contained one fiber doped with Texas Red and another fiber without Texas Red, showed homogenous distribution of the two fibers (Figure 55.6). One can observe two larger diameter fibers One of which is clearly fluorescent (Fiber 1) and another which is not fluorescent (Fiber 2). 

Surface structures SrrS, dansyl chloride cynine, Phyco[Pg.573]

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