Human CD22 also known as cluster of differentiation-22, and SIGLEC-2, GenBank Accession No. NM_001771, a.a. 20-687 fused to Fc region (a.a. 100-330) of Human IgG1 with C-terminal Avi-TagTM. and expressed in a HEK293 cell expression system. MW = 104 kDa. This protein runs at a higher MW by SDS-PAGE due to glycosylation.