Abstract: The present invention relates to a method for extracting and purifying at least one target nucleic acid contained in a sample, comprising the steps consisting of (a) putting the sample in contact with a lysis buffer optionally containing glycerol whereby a cell lysate is obtained; (b) putting the cell lysate obtained after step (a) in contact with magnetizable particles, under conditions allowing the capture of said at least one target nucleic acid by said particles; (c) washing said magnetizable particles obtained after step (b) with a washing buffer containing glycerol; (d) putting said washed particles obtained after step (c) in contact with an elution buffer, under conditions allowing release of said target nucleic acid in the elution buffer. The present invention also relates to said lysis and washing buffers.