The present invention describes the generation of an anti-idiotype single-chain Fv (scFv) antibody specific for the murine (RFB4), chimeric (SM03) and humanized (SM06) versions of an anti-CD22 antibody (the anti-CD22 antibodies). The present invention further describes the construction of a murine IgG2a/kappa immunoglobulin carrying the variable region sequences of the anti-idiotype scFv sequences. Additionally, the present invention provides a cell line capable of producing an anti-idiotype murine antibody specific for the anti-CD22 antibodies. The present invention is directed against a method for identifying and evaluating the activities and concentration of the anti-CD22 antibodies. Additionally, the present invention provides a method for evaluating serum concentration of the anti-CD22 antibodies that are being used clinically. The present invention is also directed against a method to detect HAMA, HACA and HAHA responses in patients treated with the anti-CD22 antibodies. Specifically, the present invention is directed against the establishment of a cell line expressing surface concentration of the antibody of the invention the said cell line expressing surface anti-idiotype antibodies or antibody fragments will be used as the target cell line for evaluating the functional activities of the anti-CD22 antibodies via complement dependent cytotoxicity (CDC) and/or antibody dependent cell cytotoxicity (ADCC) activities.
