ABSTRACT
Preparative and analytical processes in biochemistry require the separation of proteins, DNA, RNA, and other biochemically important substances from cell homogenates. Separation of molecules can be performed based on different physical or chemical properties such as molecular weight, particle size or shape, electric charges, or behavior in different moieties. One separation procedure relies on the different retardations of substances by percolating them through a matrix of appropriatesized beads or binding them to ligands on the matrix in a vertical column.'-2 Recent developments in this field are HPLC,3-5 FPLC,6-8 and capillary electrophoresis,9 which differ from simple column chromatography by using high or medium pressure, respectively, to force the substances to be separated through comparatively small columns.
