Steptavidin, a bacterial protein isolated from Streptomyces avidinii, is similar to egg-white avidin in its ability to bind biotin, and has been used as a replacement for egg-white avidin because of its more favorable chemical properties.
Conjugates of streptavidin are recommended for use with Biotin-SP-conjugated antibodies and Biotin-SP-conjugated ChromPure proteins.
Conjugate: Alexa Fluor® 790
Alexa Fluor® 680 and Alexa Fluor® 790 conjugates are used for very sensitive Western blots, ELISAs, and multiplexing arrays. Alexa Fluor® 680 conjugates are excited with a peak around 684 nm and fluoresce with a peak around 702 nm. Alexa Fluor® 790 conjugates are excited with a peak around 792 nm and fluoresce at a peak around 803 nm. They are the best choice for highly sensitive single or double labeling with fluorescence imaged in a LI-COR Odyssey® imager.