The sequence of the extracellular domain of human FCGRT (Ala 24-Ser 297) was fused with a C-terminal tag consisting of the AVI tag, TEV protease recognition sequence and a 10-His tag. This was co-transfected with the sequence of human B2M (Ile 21-Met 119) and the resulting FcRn heterodimer was purified. The full protein sequences can be downloaded from the product webpage.