Non-immune SJL (H-2s) spleen cells were fused with (H-2d) Balb/c 653-myeloma cells and the hybridomas were cloned by two limiting dilutions. The resulting hybrid B- cell clones were tested for their antigen presentation capability to SJL T-cell lines that were specific for either lysozyme or myoglobin. In proliferative assays, 53% of the antigen presenting B-cell clones were able to present both myoglobin and lysozyme (general presenters) while the other 47% presented specifically either myoglobin or lysozyme (specific presenters). The ability to selectively present either myoglobin or lysozyme indicates that antigen presentation at the clonal level can be specific or non-specific depending on the particular B-cell clone.