a method for the reduction of the complexity of nucleic acid pool , comprising : providing a sample with one or more nucleic acid molecules ; cutting the nucleic acid molecules by a random and / or sequence independent cutting step thereby obtaining a pool of nucleic acid fragments ; and amplifying one or more fragments of said nucleic acid molecules , wherein the one or more fragments constitute at least a fraction of all fragments of the nucleic acid molecules , wherein the amplified or amplifying one or more fragments of said fraction are divided into different subpools , and wherein the fragments of each subpool comprise a common nucleic acid feature .