In situ solution study of calcium phosphate crystallization kinetics

Calcium phosphate minerals are the main inorganic component of the bones and teeth. It is of fundamental importance to discover the effect of biomolecules on kinetics of nucleation and crystal growth of calcium phosphate crystals, which shed light on the understanding of the mechanism of biomineralization. Here, we introduce some general solution-based in situ detection methods, including analyses of chemical composition and pH and stopped-flow spectrophotometry, to study the crystallization kinetics of calcium phosphate in solution. We present the details of experimental components and considerations, such as stock solution preparation and preservation, working solution preparation, and the protocols for mixing and solution crystallization. The factors that might influence the crystallization process such as temperature control, stirring and flow rate, ionic strength, ionic species ratio, and foreign particles are also discussed here. Finally, we describe the protocols for each method and the processing of experimental data to extract the kinetics of nucleation and crystal growth. The advantages and disadvantages for each method are summarized in this chapter.