Synthesis of Immunomagnetic Nanoparticles and Their Use for Breast Cancer Cell Separation

This paper presents a novel method combining immunomagnetic separation (IMS) and real-time quantitative PCR to detect MCF-7 cells from human peripheral blood. The magnetic and fluorescent bifunctional nanocomposites (BNPs) were synthesized by through 1-ethyl-3-(3-dimethylaminopropyl) carbodiimides hydrochloride (EDAC) coupling method. The immunonanoparticles were then successfully prepared by covalently immobilizing anti-EpCAM monoclonal antibodies onto the surface of BNPs. The surface morphology of separated target cells was examined by confocal laser scanning microscope. The cell separation results showed that the synthesized immunonanoparticles could rapidly and conveniently capture the MCF-7 cells with high efficiency and specificity. To establish a quantitative PCR method for detection of MCF-7 cells, a standard curve of serial 10-fold dilutions (from 1 × 10⁵ down to 1) was constructed and showed a linear relation between Ct values and cell concentrations. Results showed that the limit detection of the immunomagnetic method was 5 cells/ml blood.