Ultrafiltration

In biology and medicine, ultrafiltration is "the separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in dialysis separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as hemofiltration or hemodiafiltration (if combined with hemodialysis)."