A chimeric anti-CD22 antibody, SM03, was constructed and shown to react with B-lymphoma cell lines.Heavy (VH) and light (VL) variable gene sequences were designed based on the parent murine anti-CD22 antibody.The VH and VL gene sequences constructed using a combination of gene-synthesis and PCR were subcloned into their corresponding heavy and light chain expression vectors.The expression vectors were then transfected into SP2/0 cells by the method of electroporation.Cell lines surviving hygromycin selection were found to express antibodies, which were then purified and characterized by sodium dodecyl sulfate-polyacrylamide, ELISA, flow cytometry, immunohistochem. and cytotoxicity anal.The results showed that the SM03 antibody had a mol. size of around 1.5 X 105 and bound to B-lymphoma cells with affinity similar to that of its murine counterpart.By using ELISA and competition flow cytometry, SM03 was confirmed to bind specifically to CD22 and did not cross-react with other B cell markers.The antibody also showed cytotoxic effect against Raji B lymphoma cells and cytostatic effect on Ramos B lymphoma cells.In conclusion, chimeric SM03 has potential to be developed as a therapeutic antibody against B-cell lymphomas.