Further Details on the Illumina Firefly

AGBT has come and gone, and with it further details of the Illumina Firefly platform have appeared. The speculation I previously posted appears to be largely correct. Genomeweb has an excellent report on what was presented by Jay Flatley. From the Genomeweb article we note “The Firefly device is essentially a CMOS sensor with nanowells. The nanowells are fabricated over photodiodes to enable DNA deposition to be aligned one-to-one with each photodiode. Clustering and sequencing then occurs directly on the CMOS chip.” and that Jay said it’s “inherently a one-channel device”. This means that they are using a single photodiode per well, unlike CrackerBio who have suggested that a triple-junction photodiode could give a decently specific signal dependent on differing wavelength.

A new chemistry has been developed for this one-channel system. He appears to have suggested that a dye needs to be cleaved and another added during imaging. That makes sense of course, but does add complexity to the chemistry. It likely means at least a slight decrease in read length/increase in error rate (all other things being equal, which of course they are not).

Using a single photodiode is the conservative move at this point, and makes sense to me when introducing an entirely new detection mechanism. Jay also said that they’ve demonstrated 150bp reads and error rates similar to the HiSeq X (to which I would say as always “show me the data”).

Announcements like this are interesting. Jay said it was because it would be difficult to keep it secret as they will be ramping up their supply chain. I’m not sure I buy that, they’re a public company and there’s always a pressure the break into new markets, release something new, and show share holders that things will get better and better.

Disclosure: While I generally try and remain unbiased. I have worked for multiple DNA sequencing companies, I continue to work in sequencing, I have interests in sequencing companies. As always, you should form your own opinions based on the facts available.