How does liquid viscosity affect the separation of particles in a centrifuge?

In a centrifuge, the viscosity of the liquid is a key factor that influences the speed at which particles migrate during the separation process.

Along with the intensity of the centrifugal field, the density difference between the particles and the liquid, and the size and shape of the particles, the viscosity of the suspending liquid directly affects the rate of migration. Generally, higher viscosity increases the resistance a particle encounters as it moves through the fluid, thereby slowing the separation process. Conversely, lower viscosity facilitates faster particle movement toward the periphery or center, depending on the relative density of the particles compared to the suspending medium.1

Achieving efficient separation requires balancing these physical properties, as the net motivating force on a particle is determined by the difference between the applied centrifugal field and the opposing buoyancy of the liquid.1