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Old 12-09-2015, 05:35 PM   #5
Senior Member
Location: US

Join Date: Dec 2010
Posts: 466

Hi GWOK, thanks for starting this thread!

We are experiencing the same problems (as is another lab in the neighborhood). The quality of the PE150 bp reads was perfectly fine a few months ago. Illumina likley has reagent quality problems at the moment.
The quality scores are now dropping considerably faster than a few months ago.
The % at which the median Q30 score curve ends (e.g. at cycle 310) seems to be a good quantifier for the problems. The curve used to end at about 60%, now often under 20%, even under 10%.

Illumina tech support did inform us that there are "NO reagent quality problems" - because all reagents individually pass QC. However they are investigating if there is a similar phenomenon ( a "non-problem"?) as with the MiSeq reagents which generate reduced read qualities scores since more than half a year now ( ).

Please keep us updated.

Last edited by luc; 12-09-2015 at 05:38 PM.
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