Summary: The recombinant heterodimer of human FCGRT/B2M comprises 385 (285 + 100) amino acids and has a calculated molecular mass of 43.5 (31.8 + 11.7) kDa. The apparent molecular mass of rh FCGRT/B2M heterodimer is approximately 35 & 12 kDa respectively in SDS-PAGE under reducing conditions.