Patent ID: 8241475

Claim:
A method to separate single- from double-stranded non-circular nucleic acid molecules from a mixture, comprising the steps of: providing a sample of nucleic acid molecules; loading said sample in an electrophoresis gel and electrophoresing in a first dimension said sample using conditions. wherein double-stranded nucleic acid fragments remain intact but conformational differences including local intramolecular secondary structures of single-stranded nucleic acid fragments are minimized, allowing separation of equally long single- and double-stranded nucleic acid molecules; denaturing said sample in said gel such that strand separation of double-stranded nucleic acids is obtained, by incubating said gel with a denaturing agent and/or at an elevated temperature above the estimated melting temperature of the sample nucleic acid fragments; electrophoresing said gel in a second dimension under conditions that prevent re-formation of double strands, to separate the fractions of single-stranded and double-stranded nucleic acids in the gel.