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Computational requirements are quite high, but OK if you have good GPUs on hand. A coronavirus sequenced sample on the fast mode without GPUs would take 3-4 hours to complete, while on the high accuracy mode days. GPU access would speed up performance considerably.

Error rate for MinIONs is still quite high (10-15%), so a human genome sequencing would be quite inaccurate in some regions.

Sequencer is quite cheap, reagents and flow cells are a little bit more expensive.


Thank you. The upfront cost of the sequencer sure makes it tempting at first sight.

My desired hobbyist use case is to key out plants, lichens and mushrooms that I find in the field. I have the bioinformatics knowhow just need the hardware. 3-4h seems lika a long time for a genome that is <30k nucleotides long. Mushrooms on average seem to have almost as many genes as coronaviruses has nucleotides. I guess partial sequences (and thus reduced comp time?) might do the trick but it's probably hard to target those partial reference sequences with a long-read method like NanoPore.

If you repeat the process many times will it reduce that error rate, or are the errors non-independent?
Unfortunately, with nanopore the errors are biased so you tend to get errors in the same places. All sequencing techniques also have error rates but some are unbiased so running a single sample through (which will usually have many, many copies of any sequence) will average out to a good read of the sequence.

Some good info on next-gen sequencing techniques: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3841808/

Still, some of the errors can be compensated for with more coverage. So if you can manage 20-30X you're left with the homopolymer problem (nanopores can't tell how long a stretch of the same repeated nucleotide is, because you can't control how long the sensed kmer stays in the pore), but lots of other types can be improved quite a lot.
Last time I looked into Nanopore the cost wasn't that much better where you'd even consider this experiment.

On the other hand, when doing a genome assembly, the Nanopore reads are good for a draft sequence and then the Illumina reads can be used to polish the sequence.

Is the error rate per base pair?

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