Abstract: The present invention provides a poly(alkylene oxide) polymer based size selective nucleic acid enrichment method for enriching target nucleic acid molecules from a nucleic acid containing sample which comprises target nucleic acid molecules and non-target nucleic acid molecules, wherein the target nucleic acid molecules are longer than the non-target nucleic acid molecules, the method comprising (a) preparing a binding mixture comprising—the nucleic acid containing sample, —a poly(alkylene oxide) polymer and—a salt and binding nucleic acid molecules to a solid phase which comprises a functional group, preferably carboxylated magnetic particles, wherein the bound nucleic acid molecules comprise target nucleic acid molecules; (b) preferably separating the solid phase with the bound nucleic acid molecules from the remaining sample; (c) contacting the solid phase with the bound nucleic acid molecules at least once with a reagent composition comprising a poly(alkylene oxide) polymer and a salt to selectively elut

Abstract: The present invention provides a poly(alkylene oxide) polymer based size selective method for enriching nucleic acid molecules having a length below a cut-off value from a nucleic acid containing sample, the method comprising: (a) preparing a binding mixture comprising —the nucleic acid containing sample, —a poly(alkylene oxide) polymer and —a salt and binding nucleic acid molecules of different sizes to a solid phase which comprises a functional group, preferably carboxylated magnetic particles; (b) separating the solid phase with the bound nucleic acid molecules from the remaining sample; and (c) contacting the solid phase with the bound nucleic acid molecules at least once with an elution composition comprising a poly(alkylene oxide) polymer and a salt to selectively elute nucleic acid molecules having a length below the cut-off value from the solid phase while larger nucleic acid molecules having a length above the cut-off value remain bound to the solid phase, wherein the concentration (w/v) of the poly(

Abstract: Subject of the invention is a method for isolating nucleic acid from a sample solution, wherein the nucleic acid is separated from the sample solution by adsorption to magnetic particles, followed by separation of the magnetic particles with the nucleic acid adsorbed thereto from the sample solution by application of a magnetic field, followed by at least one washing step (w), comprising (w1) suspending the magnetic particles with the nucleic acid adsorbed thereto in a washing solution, which is an aqueous solution, which has a total salt concentration below 100 mM and does not comprise an organic solvent, (w2) incubating the magnetic particles with the nucleic acid adsorbed thereto in the washing solution, and (w3) separating the magnetic particles with the nucleic acid adsorbed thereto from the washing solution.