Personalized genomics just got a lot more accessible. Until tonight, the cheapest genome scan was available for just under a thousand dollars. Thanks to improvements in microarray technology, 23andMe has been able to cut that cost by more than half – to $399 – well within the reach of cash-strapped grad students, frugal genealogy buffs and other not-so-early adopters.

“By taking advantage of continuing innovation we are able to introduce a new chip that will give people more relevant data at a lower price,” said Anne Wojcicki, co-founder of 23andMe. ”We are excited that we are opening doors for more people to learn about their health and ancestry and for more people to be able to participate in advancing research. It is important to democratize personal genetics and make it more accessible."

On The Spittoon blog, Wojcicki mentioned that her company has also implemented a major technology upgrade. Among other things, their new chip can check people for a condition that makes taking some drugs extremely dangerous. If you are G6PD deficient, and unwittingly take the malaria drug primaquine, you'll have a horrible reaction that may include hemolytic anemia and death.

By checking your genetic makeup before taking a new medication, you might be able to avoid that sort of nasty situation. In other words, the new test could give you a lifesaving warning.

Predicting how someone will respond to a drug before they ever take it, just by looking at their genes, is called pharmacogenetics. It is a rather new field, and not ready for prime-time yet, but I have a feeling that services like the one offered by 23andMe will greatly accelerate its development.

At some point 23andMe will start asking its clients how well they respond to particular drugs. By relating that information to their customer's genetic data, the small company's researchers may be able to identify new pharmacogenetic markers – genes that indicate how someone will react to a medication.

In order to do those studies, the personalized genetics company requires a tremendously large population to study. In other words, it needs tons of customers, and that could be the underlying reason for this incredible price cut.

But the other co-founder of 23andMe,

Linda Avey, offers a different explanation. She says that the biotech industry has its own Moore's Law, and it moves even more swiftly than the one that causes the cost of computer chips to drop as their capabilities swiftly increase. From the outset, she has suggested that the cost of the whole genome scan would drop as microarrays become cheaper and more sophisticated.

Despite the massive amount of information gathered by those chips, some people are convinced that they do not paint a detailed enough picture of our genetic makeup.

"The term 'whole genome scan' seems misleading to me," said a bioinformatics student in our comments thread. "It took C. Venter's whole, single-purpose, dedicated company many months and many millions (or even billions ?) to sequence a single human genome. And even that was subject to quite some criticism: Measured, short sequence fragments were "puzzled" together in computers by heuristic algorithms, resulting in a 'probably' correct whole sequence."

Genetics experts could argue that tests like the one offered by 23andMe are fully adequate. They make over 650,000

measurements, and that should be enough to see the big picture – or even reconstruct the whole genome with some very educated guesses. It's a bit li k coml ting this sen ence. Even though some of the information is missing, you can easily fill in the blanks.

In any case, it looks like bigger-better genetic tests are on the way.

Will the lower price drive you to try their service? What would you do with all of that information?