The rate of sedimentation of objects of various masses during rapid rotation in a centrifuge is called Vedberg unit. It is denoted by S. It stands for the first letter S of Swedish biochemist Theodor Svedberg’s name. S=1×10-13 cm/sec/dyne/gm. He was awarded the Nobel Prize in Chemistry in 1926 for his invention of the ultracentrifuge technique for colloidal materials.