A cell surface-associated protein expressed strongly on mature B-cells, follicular dendritic cells of lymphoid tissues and derived tumors, and weakly on immature thymocytes and T-lymphocytes. A variety of lymphomas display disruption of CD21-positive follicular dendritic cell networks and precursor B-cell lymphomas, Burkitt lymphomas, plasmacytomas, and hairy cell leukemias lack CD21 expression.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen typeorOne (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody orderedBlock and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.