Affinity purified Hippeastrum hybrid lectin (HHL) is consists of four subunits of identical size. It binds only to (α-1,3) and (α-1,6) linked mannosyl units of α-mannose residues. HHL reacts not only with terminal but also with internal α-D-mannosyl residues. Lectin appears to possess extended binding sites complementary to at least three 1,6-linked α-mannosyl. HHL also binds to some yeast galactomannans.
Cy5, when bound to Hippeastrum hybrid Lectin (HHL), can show the binding pattern of this lectin in cellular imaging and flow cytometry. The excitation wavelength required for Cy5 to fluoresce is high enough to avoid overlap with most other fluorochromes, making it useful for dual-labeling experiments. Because of this high excitation, there is typically less background from autofluorescence of biological specimens.