The Kinetics of β-Hematin Crystallization Measured by Depolarized Light Scattering.

Malaria is caused by Plasmodium sp. parasites transmitted by infected female Anopheles sp. mosquitoes. The survival of the parasites in the host relies on detoxifying free heme by biocrystallization into insoluble crystals called hemozoin. This mechanism of self-preservation is targeted by a certain class of antimalarial drugs, which are screened and selected based on their capacity to inhibit the formation of hemozoin crystals. Therefore, experimental techniques capable of accurately characterizing the kinetics of crystal formation are valuable. Relying on the optical anisotropy of hemozoin, the kinetics of β-hematin crystal formation through the statistical analysis of photon counts of dynamic depolarized light scattering (DDLS), in the absence and presence of an antimalarial drug (chloroquine, CQ), is described. It is found that CQ has an impact on both the nucleation and growth of the crystals.