Next generation sequencers (NGS) revolutionized the market for DNA analysis. However, the instruments’ cost has traditionally been a limiting factor for many laboratories to acquire and utilize the technology on their own bench. Instead, scientists would have to send their samples to core facilities to have them sequenced.

Personal DNA sequencers are the next iteration of NGS systems initially introduced by the same manufacturers and employ a similar technology to that behind the larger systems. The majority of the personal DNA sequencers on the market use bead sequencing to identify and map the nucleotide sequence.

In order to scale down the traditional NGS technology into a more compact instrument, some sacrifices had to be made. Personal DNA sequencers have lower throughputs and offer shorter read lengths. Nevertheless, they have opened up a completely new application arena, particularly for clinical research and diagnostics. Although current systems are not labeled for diagnostic or clinical use, they hold the potential for use for such applications, especially for point-of-care clinical testing. Illumina has been leading the charge into diagnostics and is currently seeking FDA approval for its MiSeqDx system and cystic fibrosis full-gene sequencing assay (see IBO 6/15/13).

Illumina began shipping its MiSeq personal sequencing system in the summer of 2011. The system can run up to 96 simultaneous samples by using a 96-well plate. The system is capable of producing 2 x 300 paired-end reads and up to 15 Gb of data in a single run.

Life Technologies manufactures the Ion Torrent Personal Genome Machine (PGM), which employs semiconductor technology. DNA fragments are attached to a bead. Each bead is then placed inside a well. Each well is then saturated with one of the four nucleotides. When complimentary nucleotides pair, hydrogen is released, resulting in a pH change, which is detected by the well’s electrodes.

Roche 454 Life Sciences offers the GS Junior, which has a throughput of about 35 million bases per 10-hour run, with an average read length of 400 bases. It recently introduced an automated DNA sample enrichment platform that combines Hamilton’s Microlab NIMBUS NGS workstation with Roche’s REM e-system PCR and bead hybridization platform.

Oxford Nanopore Technologies is developing the GridION and MinION systems. Both systems use nanopore sensing as their core technology, which identifies specific analytes as they pass through the nanoscale tube. The MinION is a portable and disposable device the size of a USB drive.

Personal DNA sequencers are a fast growing part of the $1.5 billion sequencing market. While the current systems are marketed for research use, the future of this market is expected to be heavily influenced by diagnostic and clinical applications.

Personal DNA Sequencers at a Glance:

Leading Suppliers

• Illumina

• Life Technologies

• Roche

Largest Markets

• Biotechnology

• Academia

• Government

Instrument Cost

• $900–$200,000