Far-red fluorescent Alexa Fluor 635 streptavidin has absorption/emission maxima of ∼633/647 nm. Streptavidin is a nonglycosylated biotin-binding protein that is isolated from bacteria and has a near-neutral isoelectric point. It is widely used to detect biotinylated probes, because it reportedly exhibits less nonspecific binding than does the glycosylated, biotin-binding protein, avidin.

View a selection guide for all Alexa Fluor™ streptavidin and avidin conjugates.