Fluorophore conjugated streptavidin

Figure 12.7 Protein-protein interaction assays performed on filled-squared ZnO NR arrays. (A) Interaction between biotinylated bovine serum albumin (BBSA) and dichlorotriazinylaminofluorescein (DTAF) conjugated streptavidin leads to strong fluorescence emission shown in panels 4 and 5. As-grown ZnO NR arrays do not show any autofluorescence. SEM micrograph of as-synthesized NR arrays is displayed in panel 1 and the corresponding fluorescence emission of as-grown NR arrays is shown in panel 2. (B) Strong fluorescence signal is visible when an alternative fluorophore, exhibiting different absorption and emission profiles than...

Gruber HJ, Marek M, Schindler H, Kaiser K. Biotin-fluorophore conjugates with poly(ethylene glycol) spacers retain intense fluorescence after binding to avidin and streptavidin. Bioconj. Chem. 1997 8 552-559. 

Incubate the slides for 1 h with streptavidin-Texas red (or other appropriate avi-din-fluorophore conjugate), diluted 1 100 in PBS-TX-BSA (or other dilution as recommended by the supplier) see Note 45). 

Streptavidin is available linked to fluorophores, such as Texas red It is usually purchased as a solution that can be used at a dilution of approx 1.200 in PBS-BSA. The solution containing the streptavidin-fluorophore conjugate is applied to the sections for 30 min Thereafter, sections are washed and treated as if they had been labeled with a fluorescently tagged secondary antibody... 

Make it visible the fluorophore label can be visualized directly using fluorescent microscopy. The biotin label (see Sect. 6.2.1) can be detected using streptavidin conjugated with an enzyme the latter must be visualized through an enzyme chromogenic system. Incubate sections with an appropriate enzyme substrate until optimal color develops (see Sect. 2.3). 

Fig. 5.2. Methods for detection of passenger-ligand interaction. (A) Fluorophore-coupled ligand (B) fluorophore-coupled antibody (C) quaternary complex generated by subsequent rounds of incubation with ligand, primary antibody, biotinylated second antibody, and strep ta-vidin, R-phycoerythrin conjugate (D) quaternary complex generated by subsequent rounds of incubation wi tli ligand, primary antibody, biotinylated second antibody, and streptavidin-coated magnetobeads. L ligand P passenger.

Figure 3.3.2 Format of sandwich ELISA for antigens (high molecular weight compounds). This format needs a capture antibody (on the microtitre plate surface) and a detector antibody, to which an enzyme (e.g. HRP) can be conjugated. Other possibilities would be that the detector antibody is labeled with a fluorophore or is biotinylated. The latter would use streptavidin-HRP in the detection step...

The secondary antibody used to develop CldU can be a biotinylated one so that signal amplification can be done. The biotinylated secondary can be detected by subsequent incubation with streptavidin conjugated to the fluorophore of choice. Conveniently, conjugated secondary antibodies raised against the appropriate primary host can be obtained from a variety of different companies in our experience, we obtain very good results with secondary antibodies from Jackson ImmunoResearch Laboratories and also from Molecular Probes. Secondary antibodies can be used at different... 

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