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.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. Griffonia simplicifolia Lectin (GSL I+II) is conjugated to HRP at an appropriate ratio to provide optimal staining characteristics.