Specificity: Recognizes a protein of 210-220kDa, which is identified as the complement receptor 1 (CR1)/CD35. This antibody is specific for a site in CR1 that is distal from the C3b-binding site, so that it is unable to block CR1 activity. It is highly specific to CR1 and shows no cross-reaction with CR2. This antibody labels follicular dendritic cells and follicular dendritic cell sarcoma. Immunogen: Intact human monocytes