Phaseolus limensis agglutinin (LBA) is isolated from lima bean seeds and purified by affinity chromatography. LBA is composed of 30,000 Da subunits, of which two are joined by a disulfide bond. Each subunit contains a cysteine residue which is required for both it’s carbohydrate- and metal-ion-binding activities. It has a carbohydrate specificity of terminal GalNAcα(1,3)Gal that elutes with N-acetylgalactosamine. LBA agglutinates blood group A erythrocytes.
Texas Red is a red-fluorescent dye and when bound to Phaseolus limensis Lectin (LBA) 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.