Abstract
A model for the transition from disordered liquid state to the solid phase has been proposed based on establishing a correlation between the concentration of precursor clusters in a saturated solution and the features of solid phase formation. The validity of the model has been verified experimentally by simultaneously studying the oligomeric structure of lysozyme protein solutions and the peculiarities of solid phase formation from these solutions. It was shown that no solid phase is formed in the absence of precursor clusters (octamers) in solution; perfect monocrystals are formed at a small concentration of octamers; mass crystallization is observed with an increasing degree of supersaturation (and concentration of octamers); further increase in octamer concentration leads to the formation of an amorphous phase.