Medicago AB Products Are Available Worldwide. For Research Use Only. Phaseolus Vulgaris Lectin M (PHA-M) is the mucoprotein variant of phytohemaglutinin isolated from red kidney bean. It contains up to 20% carbohydrates in conjugation with the protein which presents two bands corresponding to about 35 kDa according to SDS-PAGE in presence of mercaptoethanol. It is a potent mitogen used to stimulate cell proliferation in lymphocyte cultures and also has a powerful erythroagglutinating activity.