GAIIx scanning technology

[msincan]

Hi,
I remember reading about GAIIx being able to utilize dual surface scanning technology. Is dual surface scanning only available on HiSeq 2000? I gave a talk today about this and a colleague of mine brought "dual surface scanning is not available in GAx platform" to my attention but I am pretty sure I did not just make this up although I can not find a direct reference on the internet so I am not sure what the case is since I do not work with this machine hands on. Does anyone have an answer?

[GW_OK]

The GAIIx doesn't scan. Instead it images with a camera and only focuses on a single surface, even though (as somebody from Illumina said at Marco Island) there are clusters on both sides of the flowcell.

I suppose theoretically you could images both sides, but then you'd need to have two different focus levels and you'd end up taking 8 pictures instead of 4. Then again you might not be able to change the focus that finely with the current optics. It's a moot point anyway.

PS one of the main issues with bringing out the Hiseq was the ability to dual-layer scan. This meant completely changing the optical detection side of hte sequencing. The Hiseq is more like an iScan, now, I think.

[msincan]

Thank you

Thanks for the explanation I must have got that mixed up from somewhere.