Separation of colloidal particles by density gradient centrifugation: Techniques and practical guidelines

Precise separation of nano- and colloidal particles is crucial for numerous scientific, technological, and industrial applications, impacting fields such as material science, pharmaceuticals, and fundamental research. This review systematically examines density gradient centrifugation, a widely used technique for separating particle mixtures by size, density, and shape. Detailed insights are provided into the scientific principles underlying particle behavior during centrifugation, including sedimentation dynamics, particle-medium interactions, and influences of particle morphology and diffusion. The review also addresses common practical challenges encountered during gradient centrifugation, such as maintaining gradient stability and achieving optimal separation resolution. Furthermore, practical methodologies and optimized strategies are discussed to enhance the efficiency, reproducibility, and reliability of separation. The objective is to provide comprehensive, detailed guidelines that enable researchers to perform effective, accurate, and reproducible colloidal particle separations in laboratory settings.