Purified by affinity chromatography, Galanthus nivalis lectin (GNL/GNA) is composed of four identical subunits. GNL is a mannose-binding lectin, though [interestingly] it will not bind α-linked glucose. This lectin was one of the original molecules used to understand how proteins recognize carbohydrates. Galanthus nivalis is found to bind to many viral glycoproteins, making it a useful tool in HIV research studies.
Cy5, when bound to Galanthus nivalis Lectin (GNL/GNA), 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.