Abstract: Described herein are improved methods, compositions and kits for next generation sequencing (NGS). The methods, compositions and kits described herein enable phasing of two or more nucleic acid sequences in a sample, i.e. determining whether the nucleic acid sequences (which can comprise regions of sequence variation) are located on the same chromosome and/or the same chromosomal fragment. Phasing information can be obtained by performing multiple, successive sequencing reactions from the same immobilized nucleic acid template. The methods, compositions and kits provided herein can be useful, for example, for haplotyping, SNP phasing, or for determining downstream exons in RNA-seq.

Abstract: The present invention provides methods, compositions and kits for detecting duplicate sequencing reads. In some embodiments, the duplicate sequencing reads are removed.