Next-generation sequencing (NGS), also known as high-throughput parallel sequencing, is the all-encompassing term used to describe a number of different modern sequencing technologies. These include Illumina (Solexa) sequencing, Roche 454 sequencing, Ion torrent: Proton / PGM sequencing and SOLiD sequencing to name a few .
With the advent of these technologies sequencing DNA and RNA has become much more facile and affordable in comparison to the previously used Sanger sequencing. For these reasons NGS has been the game-changer in the field of modern genomics and molecular biology.
A common starting point for template preparation for NGS platforms is random fragmentation of target DNA and addition of platform-specific adapter sequences to flanking ends. Protocols typically use sonication to shear input DNA, coupled with several rounds of enzymatic modification to produce a sequencer-ready product .
Accurate quantification of DNA preparations is essential to ensure high-quality reads and efficient generation of data. Too much DNA can lead to issues such as mixed signals, un-resolvable data and lower number of single reads. Too little DNA, on the other hand, might result in insufficient sequencing coverage, reduced read depth or empty runs, all of which would incur higher costs. The quality of DNA can also vary depending on the source or extraction method applied and further reinforces the need for appropriate management of the input material. Continue reading