Clearance of NHL cells from ascites by treatment with gemcitabine and rituximab. Scid mice were injected intraperitoneally (ip) with 5 × 106 DoHH2 cells (A, top) or 10 × 106 WSU-FSCCL cells (B, bottom). Mice received 20 μg rituximab (ip) on day 3 and 120 μg gemcitabine/gm body weight (ip) on day 4 after injection of DoHH2 cells. Ascites was collected on day 18, 32 and 42. Untreated scid/DoHH2 mice died prior to day 42. Because of the slower development of lymphoma with WSU-FSCCL, mice were treated with 100 μg rituximab (ip) on day 7 and 120 μg gemcitabine/gm body weight (ip) on day 8 after injection of WSU-FSCCL cells. Ascites was collected on days 22, 34 and 51. Cells from ascites were stained with PE anti-human CD45 antibody and analyzed by flow cytometry.