MGIs iSeq: The DNBSeq-E25
MGI has some new sequencers out! Well, they did about 8 months ago… and nobody seems to care. Well I care, at least I care enough to write about it several months after they were released!
There’s a solid reason why nobody is very interested in the DNBSeq-E25. It’s a clone1 of Illumina’s least popular instrument the iSeq2.
But I like these instruments! They cater to a niche that doesn’t exist but I wish did: Low throughput, simple, maintenance free sequencing. Such platforms could easily be integrated into a sample-to-answer workflow. The kind of instruments you could imagine being used directly in clinics for infectious disease testing, if anyone was motivated to do so…
Just The Facts
Let’s see how the DNBSeq-E25 stacks up against the iSeq. The DNBSeq-E25 generates 25M 100bp reads in 5 hours. This is more than twice as fast as the iSeq with 5 times the read count. Very impressive!
At first glance, this makes it a much better sequencer. Unfortunately it’s also twice as expensive, coming in at $45K3 compared to the iSeq (~$20K):
Much like the iSeq, the E25 uses a fluidic system entirely contained within the cartridge. The only interface to the instrument is mechanical, which drives a valve on the flowcell:
According to brochure the E25 uses “self-luminous dye”s. That is a dye that generates light (on incorporation). This is very similar to the approach I expected to see in the iSeq when it was first announced. Of course luminesce has been used for DNA sequencing in academic work and commercial platforms previously, so this it’s not completely novel.
The approach may offer some advantage but MGIs claim that this “eliminates the need for lasers which can be costly” is a bit of a stretch. The MiSeq seems to use LED illumination (cheap and simple) and I suspect the iSeq does too!
On the face of it the E25 seems like a better, but more expensive iSeq. After the break, I discuss a few a further points around the E25 that I thought were entertaining and may give some insight into the thought process around this release…