Gel electrophoresis can separate
   nucleic acids that differ in size.
<P>
   DNA  fragments  created  by restriction enzymes are separated based on
   their rate of movement through a gel in an electric field.
<P>
   How  far  a  DNA  molecule  travels  is  inversely proportional to its
   length.
<P>
   After  the  current  is  turned  off, a dye is added; this reveals the
   separated bands by fluorescing in ultraviolet light.
<P>
   Review:  <A ClAsS=ACT Href="http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?20&amp;D" oNClick="popact('http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?20&amp;D');txtcolor('electrophoresis1','gray');return false;" Id=electrophoresis1><iMg sRc="/images/tutorial.gif" aLt='' boRDer=0></A>