The invention relates to a method for enriching nucleic acids with a chain length of less than 300 nucleotides, comprising the method steps: i) preparation of a fluid, preferably aqueous, phase P containing (α1) at least one nucleic acid with a length of less than 300 nucleotides, (α2) at least one component different from said nucleic acid (α1), ii) bringing the phase P into contact with an anion exchange matrix to bind the nucleic acid (α1) to the anion exchange matrix , iii) optional washing of the anion exchange matrix with a washing buffer, wherein the nucleic acid (α1) remains bound to the anion exchange matrix and iv) separation, preferably elution of the nucleic acid (α1) bonded to the anion exchange matrix to give a fluid, preferably aqueous phase P containing the nucleic acid (α1). The invention further relates to a kit for enriching nucleic acids with a length of less than 300 nucleotides, the use of said kits, the use of an anion exchange matrix and a method for treatment of a disease.
