Number and size-controlled macromolecular associations are common in biology with viruses as a typical example. We report here a novel example of artificial viruses, in which the double-helical DNA is coated with 4-nm sized neutral glycocluster nanoparticles (GNPs). The resulting "glycoviruses" are compactly-packed, well charge-shielded (zeta approximately = 0 mV), and effectively transfect cell cultures without notable cytotoxicity.