Slashdot Mirror
Breakthrough In Detecting DNA Mutations Could Help Treat Cancer, TB
vinces99 writes "Researchers have developed a new method that can look at a specific segment of DNA and pinpoint a single mutation, which could help diagnose and treat diseases such as cancer and tuberculosis. These small changes can be the root of a disease or the reason some infectious diseases resist certain antibiotics. The findings were published online July 28 in the journal Nature Chemistry. 'We've really improved on previous approaches because our solution doesn't require any complicated reactions or added enzymes, it just uses DNA,' said lead author Georg Seelig, a University of Washington assistant professor of electrical engineering and of computer science and engineering. 'This means that the method is robust to changes in temperature and other environmental variables, making it well-suited for diagnostic applications in low-resource settings.' The researchers designed probes that can pick out mutations in a single base pair in a target stretch of DNA. The probes allow researchers to look in much more detail for variations in long sequences up to 200 base pairs while current methods can detect mutations in stretches of up to only 20."
When reached for comment, Magneto promised that this would spell inevitable war between mutants and humans.
Is it patented? And as someone who is working in the field. Most diseases, even inherited ones, are not due to single mutations...
If information wants to be free, why does my internet connection cost so much?
Given that "...our solution doesn't require any complicated reactions or added enzymes, it just uses DNA," it should be unpatentable thanks to the recent Supreme Court decision.
Everything is better with chainsaws.
The link points to a university press release, I would therefore not put too much on the claim. The text in the press release is so inflated with flowery prose the subject matter looses credibility. Since the original paper is behind a pay wall most of us will never know if it was a 'breakthrough' or not. Plus I see it will be patented but the research was paid for by public funds!
Really, it comes down to what they do with the patent once they have it. They could charge a penny for it as a token licensing fee. Or they could demand 50% of all the revenue of anyone using it which would make sure it never sees use in the "parts of the world with few medical resources" (except for those nations that routinely ignore patents).
If I have been able to see further than others, it is because I bought a pair of binoculars.
That decision prevented naturally-occurring gene sequences from being patented. The "just uses DNA" solution from TFA uses DNA that has been engineered to "emit a fluorescent glow."
Being entirely non-natural, it would be eligible for patent protection.
Sequencing involves in vitro DNA synthesis. It sounds to me like they are doing nothing more than solution hybridization. e.g. denature your sample, apply it to membrane with a probe on it, and let the strands anneal to the probe. Then they get a fluorescent signal if the strands anneal properly.
My question is how they get the hybridization so specific that a single base pair difference will cause a measurable difference in hybridization. If it's as easy as they make it sound, they do this without highly controlled temperatures and buffers.
Give me Classic Slashdot or give me death!
I'm reading the paper - they found a clever way to make sure that DNA doesn't hybridize across the SNP. That ensures that in an equilibrium solution it'll be present at much smaller concentration than a fully-hybridized DNA. That is really a neat trick, but hardly a groundbreaking achievement that will revolutionize everything.
There's no genes to patent here, only a technique for identifying differences between strands of DNA and an artificially-created reference strand that's engineered to glow fluorescently.
Think of it as an efficient diff method for DNA that doesn't involve computationally-complex gene sequencing.
FTA:
The probe is engineered to emit a fluorescent glow if there’s a perfect match between it and the target. If it doesn’t illuminate, that means the strands didn’t match and there was in fact a mutation in the target strand of DNA..
So the technique will be limited to a single probe in each reaction. This could be great when all you want to check for is the presence of one or two specific mutations, but in most situations there are many different mutations that could be causing the same effect. You would have to run dozens of tests using this method to get that information. I don't see this as displacing methods that use arrays of DNA probes attached to chips: those let you check for hundreds of mutations or hundreds of species of pathogens all at the same time, but it might improve array techniques if these probes still work well when placed on arrays.
Typically, hybridization probes rely on match/mismatch similarities between one target strand, and the probe strand; when the difference is a single base pair, your signal/noise ratio can be pretty poor. But while performance is typically poorer than PCR-based assays, they can be faster and easier to run, requiring less sophisticated equipment.
This new technique uses a mechanism that simultaneously evaluates both strands of the target at once (by passing through a cross-shaped intermediate complex). Basically, it's like differential signaling -- a single-point mutation on a dsDNA segment actually produces two detectable and complementary changes, one on each strand.
This is simplifying a bit (leaving out parts like the intermediate step used to generate toe-holds for the multi-way interaction) but that's the best computer analogy I can think of for a Slashdot explanation. It's nothing world-breaking, but it looks something with practical impact, giving a nice boost to a very widely deployed molecular diagnostic technique.