Update: New ‘R9’ nanopore for faster, more accurate sequencing, and new ten minute preparation kit
Thu 26th May 2016
‘R9’ is one of many alternative nanopore chemistries that have been in development at Oxford Nanopore. It was recently released in a new flow cell which will replace the previous R7 flow cells. R9 offers greater accuracy and sequences at higher speeds, allowing users to generate more data per unit time.
As a reminder: as DNA passes through this nanopore the resulting variations in current are used to determine the sequence of nucleotides on a DNA strand.
Oxford Nanopore CTO Clive Brown held a Google Hangout that gave details of the new chemistry. Key points:
- R9 is the Oxford Nanopore name for the new nanopore ‘reader’, CsgG. This has been licensed from the lab of Han Remaut (VIB/Vrije Universiteit Brussels) and UCL.
- R9 offers improved accuracy over R7, most importantly at ‘1D’ (reading only one strand of the DNA, rather than both the template and complement strand using a hairpin adapter) [animated gif/movie]
- Accuracy is enhanced by using new basecalling algorithms based on neural networks rather than the hidden Markov model traditionally used with previous nanopore chemistries.
- Using the 1D method means that workflows are simpler; sample preparation is now reduced to ten minutes, compared to many hours for competing technologies.
- R9 has been introduced at a sequencing speed of ~250 bases per second per nanopore, compared with ~70bps for R7. This, combined with the need to only sequence one strand of the DNA, will result in much larger yields of data, opening up a new range of applications for MinION users
Rapid sequencing kit
The Rapid Sequencing Kit, combined with the R9 flow cells and real-time basecalling means that first results from a nanopore experiment can be available very soon after starting from extracted genomic DNA. The library preparation takes only 10 minutes and requires fewer consumables, and data streams immediately upon starting the experiment on the MinION. The rapid sequencing kit is currently being used by some developers in the nanopore community, and will be fully released imminently. Order it at the Store.