Proteomics  research.    3-D  map  based  on a 2-D gel  used  for  separating  proteins.    Each peak represents one protein spot on a 2-D gel.  The gel was  scanned  and spots assigned heights depending on intensity.  The gel separates proteins by their charge  and  mass  by  the  application  of  a  pH gradient and an electric field respectively.  This 3-D  analysis  reveals  individual  spots that may appear  merged on a 2-D gel plate.  A laser-guided robotic  spot  cutter  then  goes  over  the plate removing  spots  of  proteins for analysis by mass spectrometry.    Proteomics  is  the  study of the structure  and  function of all the proteins in an organism.