ActiveMax® Human 4-1BB Ligand / TNFSF9 (71-254) μBeads, premium grade (for cells) are uniform, superparamagnetic beads of 5.5 µm with streptavidin on its surface and coupled with biotinylated Human 4-1BB Ligand / TNFSF9 (71-254) Protein, expressed from human 293 cells (HEK293) and contains AA Arg 71 - Glu 254 (Accession # P41273-1 ).