Available for licensing are NIH patent pending contrast particles for use in MRI and flow cytometry to track cells migration in real time. Present cell-tracking studies rely on labeling cells with ultra-small dextran-coated iron particles that are endocytosed. The contrast agent of the present invention uses larger iron oxide particles, approximately 1 µm, situated in a tri-layer structure. The inner structure is a magnetic molecular complex of FITC (a fluorescent marker) encased in a layer of superparamagnetic microparticles, which is then covered with a shell of inert polystyrene and di-vinyl benzene coated with soluble -COOH groups. Accordingly, the particle is labeled with both a magnetic and fluorescent marker. This dual labeling permits monitoring of the molecule on multiple spatial scales, from intracellular distribution to distribution throughout the animal.