New Sequencing by Expansion chemistry by Roche
If you missed it, you may want to check out the webinar
https://sequencing.roche.com/global/en/videos/webinar-sequencing-by-expansion-technology.html
(Screenshots are from the presentation and copyright belongs to Roche)
They demonstrated going from library prep to sequencing to called VCF in 6 hours and 25 minutes. This is early days as they plan to go commercial in 2026 so we don't have a price point.
But overall, this has the potential to change the real-time sequencing paradigm by producing 2.7 Tbases per hour with average lengths of 650+bp. They have optimized the pore throughput so that the massive Xpandomer nucleotides (20 kilodaltons) pass linearly producing a clean signal peak. Homopolymers are an issue typical of nanopore sequencing but look ok up to 15bp.
This is a technology that moves the bottleneck from sequencing to processing so their plan is to move more of the processing to the instrument. With 0.5Mbp/sec, the driving cost of the instrument may be the onboard GPU compute despite the 8M sensors.
The expansion chemistry step is rate limiting despite the short turnaround so that will probably be optimized before they launch.
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- Velsera Employee
For more in depth (and more intelligent) discussion, check out these blog posts by Keith who is always excellent
https://omicsomics.blogspot.com/2025/02/roche-xpounds-on-new-sequencing.html
https://omicsomics.blogspot.com/2025/02/roche-ripple-predictions.html2 -
This is interesting and seems to have a lot of potential. How does the 6 hours and 25 minutes compare to typical processing times with todays sequencing technology and workflows?
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- Velsera Employee
Lets keep in mind this was a technology demonstration and specs may be different once it is launched and the price point will also be a factor. That said, 6.5 hours is extremely fast compared to total processing time for platforms on the market today.
This technology changes the accepted norms of nanopore sequencing and if they are successful, they can blow all competition out of the water and redefine clinical sequencing for the next decade. This is great news for precision medicine!
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- Velsera Employee
6.5 hr TAT and 2.7 Tb/hr throughput are impressive. It’ll be interesting to see how it holds up in terms of accuracy and scalability, especially for clinical settings. If SBX can deliver on both at a competitive price point, it could be a real game-changer!
Nanopore has made advancements in recent years, but challenges like homopolymer resolution and error rates are still areas of active improvement. It will be interesting to see how SBX compares in these aspects!0 -
- Velsera Employee
Great points!
Agree on the price point but early signs are that they will make it low enough for adoption. They want to co-develop software with the community like Pacbio pioneered so it has to be affordable for research purposes.
They are already getting Q39 for the fast runs. Our perception of nanopore sequencing has been based on Oxford Nanopore (ONT). What Roche have done is to redefine the standard by working on this in stealth mode since they acquired Stratos Genomics. The massive 20 KDa molecules prevent secondary structures from interfering with the throughput at the pore. This makes base calling almost trivial as the expandomers come through at a metronomic rate. This is the biggest pain point of ONT and led to homopolymer issues. That said, homopolymers will be a concern when it comes to clinically actionable loci and will probably require secondary validation.0
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