sedimentation coefficient

Symbol: s. The rate of sedimentation in centimetres per second that occurs when a solution is subjected to a centrifugal force of one dyne (10^-5 newton). These rates are extremely low and are usually multiplied by 10¹³ to give a reasonable figure. In this modified form the unit is termed the Svedberg unit, symbol S. Different molecules and cellular inclusions tend to have characteristic sedimentation rates depending on the weight and shape of the molecule. For example, the ribosomes of prokaryotes have a value of 70S and those of eukaryotes 80S.