This product is fluorescently-labeled wheat germ agglutinin (WGA). WGA is a carbohydrate-binding lectin that has high affinity for sialic acid and N-acetylglucosamine. WGA conjugates can be used to stain glycoproteins that have these sugar moieties. WGA can be used as a gram stain to fluorescently label gram bacteria but not gram- bacteria. WGA also binds to the bud scars on budding yeast such as Saccharomyces cerevisiae. CF® dyes are Biotium's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. Far-red fluorescent CF®640R dye has excitation/emission at 642/662 nm.