Sequential sequencing

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