Murine monoclonal antibodies were raised against porcine platelets in order to provide tools for investigating interactions of human blood cells and natural antibodies with porcine tissues. Hybridomas were screened by cellular ELISA on porcine platelets and endothelial cells. Positive clones were tested by flow cytometry for reactivity with isolated endothelial cells. One clone, NaM160-1A3, produced an antibody that stained porcine but not human endothelial cells and lymphocytes. The antibody bound to a 116 kDa glycoprotein on Western blot of both platelets and endothelial cells. The antigen was purified from a platelet lysate by affinity chromatography, first on a ConA column and then on a column presenting the immobilized NaM160-1A3 antibody. Two glycoproteins were obtained: one (116 kDa) was recognized by the antibody and one(150 kDa) was not. The 116 kDa protein had an internal decapeptide identical with human β1 integrin, and the 150 kDa protein had an internal amino acid sequence belonging to porcine α2 integrin. Therefore, the NaM160-1A3 antibody was directed against porcine β1 integrin and allowed the purification of the complex α2β1, also termed Very Late Antigen 2 (VLA-2). It did not recognize human β1 integrin.