Deep Sequencing - Scientific Background

Next-generation sequencing (NGS) refers to non-Sanger-based highly parallelized DNA sequencing technologies. In one experiment millions or even billions of DNA strands can be sequenced in parallel leading to very high data throughput. Here we discriminate between platforms producing rather short sequencing reads (35 – 800 bp) and technologies that aim at the longest possible read length.

Short read Sequencing

With the GS 20 system from 454 Life Sciences the first short read sequencing system became available in 2005. Since that time other companies such as Illumina, Life Technologies and others entered the market of short read sequencing systems. Short read sequencing aims at producing massive throughput with rather short read lengths. Current systems provide up to billions of sequencing reads in one single sequencing run. This technology is suitable for qualitative but in particular for quantitative studies such as transcriptome profiling, diversity studies, ChIP-Seq or mutational analyses.

Long read Sequencing

In contrast to the short read sequencing systems, long read sequencing is particularly suited for de-novo sequencing projects or to investigate complex RNA isoforms and structural rearrangements. Current systems provide read lengths up to 60 kb and are therefore well suited for the mentioned studies. The throughput of the long read sequencing is moderate in comparison to the short read platforms.