Allium sativum lectin (ASA) is purified first with affinity chromatography and then with gel filtration. It is a dimer of two subunits. ASA binds to a number of α1-2-linked mannose residues. The lectin recognizes internal mannose and binds to the core pentasaccharide of N-linked glycans. In addition, the removal of sialic acids enhances binding activity.
Texas Red is a red-fluorescent dye and when bound to Allium sativum Lectin (ASA) can show the binding pattern of this lectin in cellular imaging applications. There is very little overlap between the emission spectra of Texas Red and FITC making this combination ideal for dual-labeling experiments. Rhodamine dyes, such as Texas Red, are more photostable and less sensitive to pH change when compared to other dyes such as fluorescein.