For transfection of adenovirus GoldMAN is a gold/iron-oxide composite nanoparticles as a new type of magnetic beads for in-vitro and in-vivo applications. Au particles with sizes of less than 10 nm are homogeneously immobilized on the surface of support magnetic nanopaticles. As the gold part can be used as a general tag for various functional molecules, the composite nanoparticles can be easily functionalized for each application. We are developing magnetic beads for separation/purification of biomolecules, immunodiagnosis, gene transfection reagent, MRI contrast agent and so on. The dispersibility and magnetic property of the magnetic beads are optimized for each application. For example, it can apply for transfection of adenovirus.