Soybean Agglutinin (SBA), Fluorescein, 2 mg. SBA preferentially binds to oligosaccharide structures with terminal alpha- or beta-linked N-acetylgalactosamine and, to a lesser extent, galactose residues. Binding can be blocked by substitutions on penultimate sugars, such as fucose attached to the penultimate galactose in blood group B substance. Fluorescein-labeled Soybean agglutinin has an appropriate number of fluorochromes bound to provide the optimum staining characteristics for this lectin. This conjugate is supplied essentially free of unconjugated fluorochromes. The excitation maximum is at 495 nm and the emission maximum is at 515 nm. The recommended concentration range for use is 5–20 µg/ml.