Method and apparatus for the purification of extra-chromosomal nucleic acids sequences

A method for obtaining one or more extra-chromosomal nucleic acids from cells and comprising the steps of:

• a) optionally cultivating cells comprising the extra-chromosomal nucleic acids of interest,
• b) disintegrating the cells by mixing the cells in suspension with a lysis medium to form lysed cells,
• c) neutralizing the lysed cells by adding a neutralization solution to said lysed cells to produce a first cells lysate mixture comprising a soluble fraction and a precipitate,
• d) optionally further precipitating contaminants away from the extra-chromosomal nucleic acids of interest to obtain a second cells lysate mixture, by mixing the first cells lysate mixture with a solution containing one or more salt(s), wherein the salt(s) comprise one or more of CaCl2), MgCl2, ZnCl2, SrCl2, BaCl2, LiCl, ammonium acetate, ammonium sulfate, sodium sulfate and magnesium sulfate,
• e) collecting the cells lysate mixture obtained from step c) or from step d),
• f) separating the soluble fraction comprising the extra-chromosomal nucleic acids of interest of the cells lysate mixture from the precipitate in a separation tank, and
• g) recovering the separated soluble fraction comprising the extra-chromosomal nucleic acids of interest,
• wherein the separation step f) consists of dissolving a gas in a liquid aqueous medium under a pressure higher than atmospheric pressure followed by injecting the liquid aqueous medium comprising the dissolved gas into the cells lysate mixture contained in the separation tank.