Patent ID: 6958217

Claim:
Method for obtaining at least one single stranded polynucleotide tag from a biological sample, in a form suitable for further use of said tag, said method comprising the steps of i) providing at least one double stranded polynucleotide, wherein the polynucleotide is selected from the group of polynucleotides consisting of polynucleotides comprising complementary DNA (cDNA), polynucleotides comprising genomic DNA, and polynucleotides comprising extra-g-enomic DNA, ii) contacting and cleaving at least one of the complementary strands of the double stranded polynucleotide provided in step i) with at least one cleavage agent capable of recognizing a double stranded polynucleotide comprising complementary polynucleotide strands and cleaving only one of the strands of the polynucleotide provided in step i), thereby obtaining a nicked double stranded polynucleotide which comprises a single stranded polynucleotide tag, and thus obtaining at least one single stranded polynucleotide tag, (iii) isolating the tag, and retaining said tag for further use.