This product is wheat germ agglutinin (WGA) labeled with Biotin. 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 label gram bacteria but not gram- bacteria. WGA also binds to the bud scars on budding yeast such as Saccharomyces cerevisiae.