The invention relates to adaptors for sequencing nucleic acids. The adaptors may be used to generate single stranded constructs of nucleic acid for sequencing purposes. Such constructs may contain both strands from a double stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) template. The invention also relates to the constructs generated using the adaptors, methods of making the adaptors and constructs, as well as methods of sequencing double stranded nucleic acids.