Erythrina cristagalli lectin or agglutinin (ECL/ECA) is affinity purified lectin consists of two subunits with molecular weights of 28,000 and 26,000. ECL binds to carbohydrate structure in membrane and serum glycoproteins of mammalian cells. The shape of the lectin binding domains may resemble cavity type with Galβ1->4GlcNAc as the core binding site with additional one to four sugar subsites and is most complementary to a linear trisaccharide. Some Galβ1-related oligosaccharides are the major structures for lectin binding. Lectin binding activity can be abolition through salic acid substitution. This allows for specificity to fractionate and isolate mammalian glycoproteins.
Horseradish peroxidase (HRP) is a 40 kDa protein that catalyzes the oxidation of substrates by hydrogen peroxide, resulting in a colored or fluorescent product or release of light as a byproduct of the reaction. It is most commonly used for blotting, immunoassays and immunohistochemistry methods. Erythrina cristagalli (Coral tree) Lectin (ECL/ECA) is conjugated to HRP at an appropriate ratio to provide optimal staining characteristics.