Investigation of Virus Crystal Growth Mechanisms by<i>In Situ</i>Atomic Force Microscopy

Abstract

For the first time, virus crystal growth dynamics and morphology have been investigated in real time on the nanometer scale. Individual monomers on the (111) face of cubic satellite tobacco mosaic virus (STMV) crystals were resolved and used to determine crystal packing. Growth of STMV proceeded by two- and three-dimensional nucleation to formed ``stacks'' of islands. No dislocations were observed. Small islands provided an estimate of critical radius size and the free energy of the step edge, \ensuremath{\alpha}. Step advancement rates were used to determinate the kinetic coefficient \ensuremath{\beta}. Images illustrate mechanisms for defect incorporation and suggest factors that limit growth rate and uniformity.