Normal human B lymphocytes and Epstein-Barr virus-transformed B-cell lines can produce reactive oxygen species such as superoxide if treated with phorbol myristate acetate (PMA) or with the surface immunoglobulin cross-linking agents protein A and anti-immunoglobulin. Here, we investigated under which conditions specific antigen, the natural ligand of surface immunoglobulin, can stimulate an oxidative burst in monoclonal Epstein-Barr virus-transformed B-cell lines producing antibodies of known specificities. After a short lag time of 1-2 min, exposure to the specific antigen stimulated a prolonged oxidative burst (tmax 30-90 min), as measured by Lucigenin-enhanced, superoxide dismutase-inhibitable chemiluminescence, in the corresponding line only. The effect was induced in each line if the specific antigen was immobilized to a solid support. Except in one line in which antigen also stimulated an oxidative burst if presented at relatively high density on a soluble carrier, soluble antigen did not induce B-cell oxidase activation. This suggests that normal, non-transformed B lymphocytes also require interaction with relatively dense deposits of specific antigen for activation of their oxidase.