Currently we have achieved spatial resolution of approximately 20 micrometers at a detection distance of nearly 1 cm for isolated magnetic samples. Specific cell uptake of ligand-conjugated magnetic particles is resolved from physisorption without sample separation. We have also studied force-induced dissociation of noncovalent bonds between antibody and antigen molecules. Well-defined binding forces were obtained. Re-binding experiments were performed to confirm the specific dissociated bonds, a unique advantage over single-molecule techniques such as optical tweezers and atomic force microscopy.5 Furthermore, we will report our most recent results on dissociating magnetically labeled DNA duplexes.