Buoyancy Effects in Centrifugation

Buoyancy Effects in Centrifugation describes how differences in particle density relative to surrounding medium density influence sedimentation rates and equilibrium positions during centrifugal separations, with particles more dense than the medium sedimenting outward while less dense particles float inward, determining effective particle separation based on density differences.

The biopharmaceutical industry considers buoyancy effects when developing centrifugation methods for viral vector purification, cell harvest, and density gradient separations. Adeno-associated virus purification using caesium chloride or iodixanol density gradients exploits density differences between full genome-containing capsids and empty capsids enabling separation of therapeutically active from inactive particles. Cell harvest centrifugation must account for mammalian cell density differences from culture media. Analytical ultracentrifugation exploits buoyancy to characterise macromolecular properties in solution. Gradient media selection requires matching density and osmolality to preserve biological activity while achieving desired separation. As gene therapy manufacturing scales and empty capsid removal becomes a critical quality requirement, buoyancy-exploiting separation methods continue providing essential purification capabilities.