 In 1954, a fractionation column was introduced by Kepes the resembled a CCC column divided into chambers with perforated plastic disks.Similar DCCC-type instruments have been created by A. E. Kostanyan and collaborators which employ vertical columns that are divided into partitions with porous disks.Once the columns are filled with stationary phase, the mobile phase is pumped through, not continuously but, in pulses.