Griffonia simplicifolia lectin (GSL I+II) is affinity puritied from a woody climbing shrub native to Africa. It consists of both lectins GSL I+II. GSL I+II shows specificity for blood group B greater than blood group A1. This lectin interacts with pulmonary microvascular endothelial cells, but does not readily interact with pulmonary arterial endothelial cells. This binding pattern has been successfully utilized to enrich cell populations in vitro that possess functional behaviors characteristic of those seen in vivo.SeparoporeÂ® macrobeads are larger size (160-250 micron) than average agarose beads that facilitate coupling of cells and organelles and enzymes. Affinity-purified Griffonia simplicifolia Lectin (GSL I+II) was immobilized on 4% agarose macrobeads with proper configuration and stability of the lectin.