Method for generating a stranded RNA library

The invention relates to a method for preparing a strand-specific library from an nucleic acid or preferably RNA sample, for RNA comprising the steps of: (i) optionally fragmenting said RNA sample, (ii) generating a plurality of first cDNA strands by subjecting said fragmented RNA to reverse transcription by using a reverse transcriptase and first oligonucleotide primers, (iii) generating a plurality of second cDNA strands by using a DNA polymerase, second oligonucleotide primers, and the plurality of first cDNA strands, and (iv) ligating adapters to the 3′ and 5′ termini of the of double-stranded cDNA, (v) wherein the first cDNA strand allows no adapter ligation at its 5′ terminus and said second cDNA strand allows adapter ligation at its 5′ terminus, or vice versa, and, (v) optionally cloning, sequencing or otherwise using the strand-specific library. The invention also relates to a kit for preparing a strand-specific library from an RNA sample, wherein said kit comprises, (i) random oligonucleotide primers comprising a 5′ terminus nucleotide which allows no adaptor ligation, (ii) random oligonucleotide primers comprising a 5′ terminus nucleotide which allows adaptor ligation, (iii) optionally a reverse transcriptase for synthesizing a first cDNA strand complementary to the template RNA, (iv) optionally dNTPs, and (v) optionally a DNA polymerase.