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Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

extremetech.com

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Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#71

Post by gte910h »

jessriedel wrote: post #47
jwr wrote: post #42

Does anybody know how to escape their horrible "mobile" version that they force onto ipad users? It can't even be zoomed :-( More and more often I find myself not reading articles because someone thought it would be a great idea to create a non-scrolling, non-obvious, paginated "iPad format" with additional misleading and unintuitive buttons looking like native ones but doing something different. Sorry for the rant.…

I'm considering buying an iPad, and I have a question: is there no browser on the iPad that allows you to choose whether you want to the mobile version or the regular version? If not, that's almost a deal breaker.

You can use bookmarklets in safari as well usually.

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#72

Post by skosuri »

brodney wrote: post #33
colanderman wrote: post #18

Earlier quoted context omitted.

DNA is 3D. Flash drives are 2D.

Flash drives also have all of the necessary equipment for it to be read. I wonder how much data per gram the actual storage part of the flash drive actually is. I doubt it's better than DNA, but I think it might be disingenuous for the article to be offering the analogy to hard drives without taking into account the extra read/write hardware.

agreed, it should be comparied to other arhival media like tape drives; but it's still pretty similar; we compare in our paper a hard drive platter rather than a drive itself. even then we are approximately ~million fold more dense

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#74

Post by sp332 »

refurb wrote: post #62
sp332 wrote: post #30

Earlier quoted context omitted.

I've got a few trillion cells in my body that say it's incredibly stable.

Snarky reply: You've sequences every single one of those cells and confirm that the DNA all matches? Non-snarky reply: There is a huge difference between phenotype stability and genotype stability. Take 100 cells from your body and you'll find hundreds if not thousands of genetic differences between them (single mutations).

There are 3 billion base pairs in each copy of human DNA. Looks like only ~60 of them change from one generation to the next. http://www.nytimes.com/2010/03/11/health/research/11gene.htm... Just making the 4 trillion cells in my body means that each would have to be copied an average of 41-42 times. Probably some cells get replaced more often and others have a shorter path, so I'm not sure how many times DNA is duplicated before it gets to human reproduction. But going with averages: 41 * 3,000,000,000 / 60 means 2,050,000,000 copies per error. That's a few orders of magnitude worse than a modern hard drive but not exactly shabby.

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#75

Post by vph »

ChuckMcM wrote: post #36

I really liked their paper. Its a bit less over the top than the extremetech guys but hey, that is the difference between pop journalism and science. Clearly with some form of fountain code or LDPC codes you will be able to get the data back, but what struck me is that I always thought of DNA as relatively unstable, in the sense that cells decay/die etc, but the fact that just sitting there, DNA which isn't expressin…

do you have a link to their paper?

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#76

Post by sadga »

shinratdr wrote: post #48
colanderman wrote: post #17

If you store data onto 50 DNA strands, can you always read back all the data from all 50 strands, or does one need to store multiple copies of each in case the sequencer can't "find" a particular strand? If one does need multiple copies, it would seem that this method suffers from the coupon collector's problem [1] (i.e. to collect all 50 strands requires collecting 225 random strands on average), and that the retrie…

HN formatting breaks the first Wikipedia link by removing the apostrophe. I ran it through a link shortener as a workaround. http://cl.ly/1r153b103k2P

Someone modified Wikipedia as a workaround.

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#77

Post by sadga »

mhb wrote: post #39
scarmig wrote: post #37

Earlier quoted context omitted.

So, we could end up with a (drum roll please) stenographic stegosaurus? Edited to add: Ruined my own punchline. Steganographic stegosaurus, damnit!

It's even better - it would be a steganographic stegosaurus.

Since we are using DNA to record information of life experience, it's in fact a steganographic stegosaurus stenographer.

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#78

Post by skosuri »

InclinedPlane wrote: post #59
conanite wrote: post #2

They're using T and G for a 1, and A and C for a 0; why not double the density and get two bits from each letter? T = 00 G = 01 A = 10 C = 11 for example.

I'm not sure exactly why they decided on that encoding, I suspect there is some technical reason such as error tolerance.

it's to avoid sequence features which are problematic like high GC content

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#79

Post by sadga »

whatgoodisaroad wrote: post #57
dsirijus wrote: post #53

Why binary if DNA naturally has 4 bits?

Bases can only pair with one other base. Adenine can only pair with thymine. Guanine can only pair with cytosine. Knowing one base implies the other, so there are only two possible pairs.

But there are two strands, and each half-pair is fixed on one side.

Re: Harvard cracks DNA storage, crams 700 terabytes of data into a single gram

#80

Post by InclinedPlane »

skosuri wrote: post #78
InclinedPlane wrote: post #59

Earlier quoted context omitted.

I'm not sure exactly why they decided on that encoding, I suspect there is some technical reason such as error tolerance.

it's to avoid sequence features which are problematic like high GC content

Ah, interesting. In natural DNA this is achieved by using a more complex encoding scheme (3 base pairs -> one amino acid), combined with the vast majority of DNA not encoding genes directly.
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