How The NEXT Generation DNA Sequencing Might Work

High throughput DNA sequencing will be available soon ( probably <5 years). 
Today at my lab, albeit with no sound card, I greatly enjoyed seeing a short video of how one next generation DNA sequencing technique works.

In dramatic contrast to current techniques, the DNA which is being analyzed does not need to be amplified. These so-called single-molecule methods smash the dna into tiny bits, just a few dozen bases long.  Using solid-support and microarray fluorescence they can then sequence it.  To do a single human DNA set (23 chromosomes) requires analyzing 3000000000 "letters" (A, T, G, C) that need to be checked one at a time.

A little history:  The Human Genome Project, using pipettes, test tubes, enzymes, incubators, was able to analyze the DNA of one anonymous cell donor from Buffalo, starting in 1990 and finishing in 2000, crossing the finish line with a total time of 10 years.  Then Craig Venter, the CEO of TIGR/JCVI analyzed his own (or rather his company did) finishing by 2007.  Last month I read that the fifth ever human DNA had been completed, this time of a Korean man.  According to the article in Nature (Aug 20, 2009 ) it cost $200,000 to complete and took six-weeks on a trio of robotic, high throughput Illumina Genome Analyzers.

As a quick of how much data these labs are dealing with, I did a crude experiment: I tried just saying letters from a printed page.  I was able to sustain a rate of  4 spoken letters per second.  At that rate it would take me 23.8 years to say my DNA sequence out loud. ( I was actually a little disappointed; I thought I was going to get some even more outlandish number!)  Bottom line though, I  lost badly, even compared to 1990s era gene sequencing (which was, admittedly a worldwide project trumpeted at the time as being the closest modern thing to the Apollo Moon Missions).

Let me know if the above link to the movie works for you. 

For true DNA fans, here (  link  )is a review of the technical questions that will hopefully now be answerable with relatively cheap and fast Next Generation Sequencing Technology (NGST).  My favorite newly-solveable question: where did social insects come from? (preliminary answer: heightened expression of maternal caring-genes throughout the entire swarm). 

Completely unrelated but discovered by chance just now, probably the most controversial article ever for The Journal of Trends in Ecology and Evolution: Exploring the Evolutionary Consequences of Same-sex Sex: Lessons from the Animal Kingdom  , a typical example of why chemistry class doesn't grab kids attention the way that biology class does.

And here's a completely different NGST strategy, this one from Pacific Biosciences.:click on the link at the lower right of the page that says 4:05 minute Technology Demo.  

Comments

[Denise]

My ex husband, myself, my daughter Abi and my son Evan were one of the first families that were genetically tested in 1992. We were thankful that there wasn't anything with our then 5 month in utero baby and our 2 year old daughter, but not half as excited as the doctors and geneticists at Henry Ford. I didn't understand it at the time. The sheets they gave us showing the probability of known genetic conditions passing on ( diverticulosis)and not (Beta Thalessemia).

[Denise]

whoops- the sheets were interesting but intimidating.