anti-B-Cells (Subset) antibody (FITC): Indeterminate MAb BB6-10A10 stains the following percentages of surface immunoglobulin (sIg) positive cells in porcine lymphoid tissues: 11-15 % in peripheral blood, 22-23 % in mesenteric lymph nodes, 79-87 % in ileal Peyer's patches (ILPP), 6-17 in spleen, and 0 % in thymus.1 While identification of the antigen(s) that are found predominantly on ILPP B cells and which are recognized by BB6-10A10 is speculative, the antibody appears to react with an immature population of B cells in the follicles of ILPPs and with a subpopulation of sIglow B cells in lymph nodes.