INVESTIGATION OF VIRUS CRYSTAL-GROWTH MECHANISMS BY IN-SITU ATOMIC-FORCE MICROSCOPY

For the first time, virus crystal growth dynamics and morphology have been investigated in real time on the nanometer scale. Individual mono mers on the (111) face of cubic satellite tobacco mosaic virus (STMV) crystals were resolved and used to determine crystal packing. Growth o f STMV proceeded by two- and three-dimensional nucleation to formed '' stacks'' of islands. No dislocations were observed. Small islands prov ided an estimate of critical radius size and the free energy of the st ep edge, alpha. Step advancement rates were used to determinate the ki netic coefficient beta. Images illustrate mechanisms for defect incorp oration and suggest factors that limit growth rate and uniformity.