Comment Re:Nice improvement (Score 1) 34
Hmm, well your comment made me go and read the paper. It is interesting because they focused on an important part of the DNA storage process, which is deposition and recovery. And yes, there are a few neat innovations, like the tape system, the partitions, and the zeolite encapsulation.
However, the limitation remains DNA reading and writing, which is A) much longer than the deposition process, making gains in the deposition process almost insignificant, and B) requires careful temperature control such that any hopes to do this at room temperature are pretty much moot. It wasn’t the focus of the paper, so it’s not fair to say they glossed over it, but they did bury it in the methods. A few key limitations:
- They used DNA Fountain to encode the data, which offers a high storage potential, but they also limited it to 100 bp oligos so that the DNA strands would be accessible with current oligo synthesis technology. So for their test, a 50 KB file required 5000 100 bp oligos. The maximum that has been reached using this approach is around 2 MB with 72,000 200 bp oligos. The data densities that they talk about in these papers is a theoretical bits per nucleotide that is extrapolated out to number of nucleotides in a gram of DNA and therefore a theoretical maximum bits per gram of DNA. It is nowhere near a practical reality, though.
- To synthesize these oligo arrays of 3000 - 5000 oligos per array, they contracted them through Twist. It has been a while since I have worked with Twist, but these oligo pools cost on the order of $1500-$2000 per pool to synthesize, it takes weeks to months, and the failure rate is fairly significant.
- To read back the oligos they used Illumina sequencing. This is a multiple day process that also costs thousands of dollars in consumables. And for this application the error rate is significant. So instead of taking the raw sequence reads as the data, they mapped the reads to a known reference. Which means they weren’t actually reading the data, just confirming it.
Bottom line: while it is interesting to see people thinking about some of the physical aspects of a DNA storage device, and I like a lot of the ideas they have proposed here, this technology isn’t going anywhere until we have major breakthroughs in DNA synthesis and sequencing capability. And when we do it will have impacts far and wide, beyond just DNA storage.