Rapid-Fire DNA Sequencing Moves into Reality

Attention fans of CSI and all of the television dramas featuring ubergeek forensic scientists whipping out DNA sequences like grandma made a batch of chocolate chip cookies at lightning speed and little fuss - it is fiction. Until maybe now, with the development of what is being called an "ultrafast" means of DNA sequencing on a chip, where 600 base pairs can be analyzed in just 6.5 minutes.

DNA sequencing is commonly done using a process called electrophoresis, which involves a large array of reagents to tease apart the DNA double helix into smaller strands, running them through a bath of gels with an electrical current passing through it, then seeing where the gel is stained. Each set of alleles (the set of base pairs that make up a gene) moves at a different rate of speed through the gels, and stain it at specific locations, which can then be compared against a separate sequence.

This is a time-consuming and expensive process, taking several hours and thousands of dollars in chemicals, not to mention a well-paid, specially trained technician, which are the primary reasons that real-world crime labs don't run DNA analyses on a widespread basis. And the devices are massive, sometimes filling entire rooms depending on how many alleles are simultaneously being analyzed, with a constant need to re-load gels and reagents every time another section of DNA is sequenced.

In 2006, the estimated cost for sequencing just one person's entire genome (full set of DNA) was $10,000,000 to analyze the estimated 11 million genes each person has comprised of roughly 3 billion base pairs.

That could be coming to an end according to the research conducted in the lab of Dr. Annelise Barron while she was at Northwestern University and reported in the early online edition of the Proceedings of the National Academy of Science January 9, 2008. (Dr. Barron has since moved her laboratory and research to Stanford University and is continuing her line of research there.) Ultimately, Barron hopes to drop the cost of sequencing a single person's genes to $1,000 or less.

Dr. Barron's team has created a means of loading sequencing technology onto a chip, lowering the cost for sequencing, cutting the time required dramatically, and creating a basis for a single device that could load up cartridges of chips to massively analyze large portions of a person's genetic code in a matter of minutes.

Barron's long term goal is not geared toward forensics, but to medicine. "The ultimate long-term goal of this investment is to create new technologies that will allow a full or partial genome sequence determination to become part of a standard physical examination and to facilitate personalized medical care tailored to an individual's unique genetic makeup," she said in a review of her lab's work in Electrophoresis.