Abstract: A kit and a method for enriching target nucleic acid sequences from a biological sample are disclosed. The method includes preparing, and contacting with the biological sample, a first RNA probe set and a second RNA probe set respectively targeting both of the two antiparallel strands of a duplex segment in each target nucleic acid sequence. Each RNA probe in the first RNA probe set and the second RNA probe set can be generated by chemical synthesis or by in vitro or in vivo transcription, and can be biotin-labelled to thereby allow capturing of the target nucleic acid sequences by magnetic beads labelled with streptavidin, or can be engineered to a microfluidic channel to facilitate the capturing. The method can be applied to capture double-stranded nucleic acid sequences or single-stranded nucleic acid sequences having duplex segments, and the nucleic acid sequences can include DNAs, RNAs, or DNA-RNA hybrid molecules.

Abstract: A method and kit for constructing a barcoded single-stranded DNA library are disclosed. The method includes preparing single-stranded DNA molecules each having a dephosphorylated 5? end, ligating a first adaptor to a 3? end of each single-stranded DNA molecule, and synthesizing a complementary strand of each single-stranded DNA molecule ligated to the first strand of the first adaptor. The kit includes the first adaptor having a first strand, which includes, from a 5? end to a 3? end, a phosphate group, a barcode sequence, and a first primer recognition sequence. The kit also includes a DNA ligase for a ligation between the 5? end of the first strand of the first adaptor to each single-stranded DNA molecule, and a first primer for the synthesis of the complementary strand. The method allows for analysis of rare mutations and from nucleic acid samples of low quality and quantity.