iFluor(TM) 840-streptavidin conjugate

AAT Bioquest's iFluor(TM) dyes are optimized for labeling proteins, in particular, antibodies. These dyes are bright, photostable and have minimal quenching on proteins. They can be well excited by the major laser lines of fluorescence instruments (e.g., 350, 405, 488, 555 and 633 nm). Streptavidin conjugates are widely used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids and other molecules since streptavidin has a very high binding affinity for biotin. A variety of the complementary biotinylated reagents are available from numerous commercial vendors. This iFluor(TM) 840-streptavidin conjugate comprises streptavidin (as the biotin-binding protein) with iFluor(TM) 840 covalently attached (as the fluorescent label). It is commonly used as a second step reagent for indirect immunofluorescent staining, when used in conjunction with biotinylated primary antibodies. iFluor(TM) 840-streptavidin conjugates has fluorescence excitation and emission maxima of ~836 nm and ~876 nm respectively. These spectral characteristics make it an excellent alternative to IRDye(R) 800CW (IRDye(R) 800CW is the trademark of Li-COR) due to its much longer excitation wavelength (making it much more tissue-penetrating than IRDye(R) 800CW). It is a very valuable tool for biotin-streptavidin-based biological assays and tests.