Expression of CD28 in murine myeloma cell lines.

Each myeloma cell line was stained with either mouse IgG1-phycoerythrin (Becton Dickinson) or antimurine CD28-phycoerythrin (Pharmingen). The gray shaded area reflects the histogram of cells stained with mouse IgG1-phycoerythrin. The black shaded area reflects the histogram of cells stained with anti-CD28 phycoerythrin.