An apparatus and a method for obtaining a (poly)nucleotide sequence of interest include steps of cultivating hosts cells to produce a nucleotide sequence of interest and harvesting these cells, introducing these cells in a passageway and disintegrating them in a continuous process. In the continuous process, performing in the passageway a precipitation of contaminants by a mixing of the disintegrated cells with a solution containing one or more salt(s) and obtaining a mixture and allowing a precipitate to separate from the solution of this mixture, preferably to float and/or to sediment from the solution of this mixture for 1-48 hours and pumping out a soluble material from this solution, while excluding recovering the precipitate.