Affinity-purified Amaranthus caudatus (ACL/ACA) is a dimer glycoprotein made up of two subunits. ACL has preferential specificity to oliogsacharrides containing the galactosyl disacharride GalÎ²3GalNAc. ACL tolerates sialic acid substitution at the 3 position of galactose in the â€œTâ€ antigen. It does not have specificity for blood groups but does have a higher affinity for type O erythrocytes over B and A. Cy3 can be used to viualize the binding pattern of Amaranthus caudatus Lectin (ACL/ACA) in cellular imaging and flow cytometry. Cy3 is more photostable than many other flourophores and can be seen with TRITC filter sets. It is commonly combined with green-fluorescent dyes for dual-labeling.