Abstract: Scope of this study is to describe a simple, rapid, accurate, inexpensive and easily available in vitro method based on magnetic nanoparticles and magnetic cell separation principle to quantitative analysis the cell surface antigen expression of ovarian cancer cells surface (MUC1). In this work, superparamagnetic iron oxide nanoparticles (SPIONs) attached to monoclonal antibody (mAb) C595 that binds to ovarian cancer cells. Conjugation of mAb C595 to commercial SPIONs was achieved using a heterobifunctional linker sulfo-SMCC. The capability of the method was compared with flow cytometry as a gold standard and showed that both methods provide approximately the same results. This demonstrates the high potential of antigen-specific (anti-MUC1 expressing ovarian cancer) magnetic cell separation of C595 mAb coated with SPIONs-C595 for quantitative cell surface antigen detection and analysis. Overall, SPIONs-C595 nano-probe is potentially both, a selective ovarian molecular imaging tool as well as a therapeutic agent.