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Thread | Thread Starter | Forum | Replies | Last Post |
low Q30 in index, miseq v3 600 | cnano | Illumina/Solexa | 3 | 06-05-2019 01:43 PM |
Miseq v3 600 cycle kit - poor read 1 quality | incognitos | Illumina/Solexa | 3 | 11-09-2016 10:46 AM |
Problems with kit 600 cycles | Mario Moreno | Illumina/Solexa | 14 | 04-22-2015 04:12 PM |
MiSeq error rate for 600 cycle PE | Luvs_2_sequence | Illumina/Solexa | 27 | 09-29-2014 12:53 PM |
Performance improvements | perencia | Bioinformatics | 5 | 07-02-2010 07:08 AM |
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#1 |
Junior Member
Location: Scotland Join Date: Jan 2013
Posts: 8
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I have heard a rumour that the long standing MiSeq v3 600 bp kit chemistry problems which led to poor quality read 2 data have recently been solved by Illumina. Anyone know if this is true?
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#2 |
Jafar Jabbari
Location: Melbourne Join Date: Jan 2013
Posts: 1,238
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It is true and for high diversity libraries output is according to specification. Amplicon sequence quality also has improved but as before cluster density should be reduced and spiked in with PhiX.
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#3 |
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Location: New England Join Date: Jun 2012
Posts: 200
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I just started my first 600-cycle run in over a year so hopefully it's true! I'll try to update in a couple of days when it's finished.
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#4 |
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Location: america Join Date: Apr 2015
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Can anyone confirm this? I need to do some 2x300 sequencing for Ig RNA-seq experiments. Would be awesome if I could use the MiSeq.
Thanks, |
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#5 |
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Location: Cambridge Join Date: Sep 2010
Posts: 116
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Yes, the last few runs were way better (touch the wood).
If doing amplicons, please use a lot of phiX or shotgun library (up to 20%) (esp. if fist 25 bp's are the same). It would not hurt, and gains in data quality/yield from better dephasing calculation far outweigh the losses from 5%-20% phiX sequence spike in. If doing cDNA amplicon analysis: make sure you do not use oligoC oligos in your amplicons, because the read quality would go through the floor if there are 10-14C's or G's in a row, and you may also get non-specific amplification of rRNA (rcDNA), reducing usable data yield by 1-2 orders of magnitude. Also lower the loading density for 500-600bp amplicons, if you need high quality reads for your analysis. Obviously do not forget, that the longer the amplicon or the read is, the more sensitive it becomes to the DNA sequence content. |
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#6 |
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Location: Walnut Creek, CA Join Date: Jan 2014
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#7 |
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Location: Scotland Join Date: Jan 2013
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Thanks to everyone for their positive replies, that is very good news. We have ordered up a 600 bp kit and will test it ourselves soon and let you know how we get on.
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#8 | |
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Location: Cambridge Join Date: Sep 2010
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2. If you can cope with 2-4% systematic errors - Oxford Nanopore 2D. 3. There used to be Roche's systems - FLX+ and Junior, but the reagents for them are no longer available... :-( |
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#9 |
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Location: Scotland Join Date: Jan 2013
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#10 |
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Location: New England Join Date: Jun 2012
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Not good
![]() It was an amplicon run, but the cluster density was good (~600K) with 20% phiX, so I expected the Q30 to be much better than 64% overall. It was only 54% for Read 2. Both reads only got out to about 150 bp before dropping off dramatically. The investigator decided it was definitely not worth trying to use the 600-cycle kit again! |
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#11 | |
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Location: Scotland Join Date: Jan 2013
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Anyone else with recent experience running the 'new' 600 bp kits? We plan to use one this week or next.... Last edited by jhi_pete; 02-21-2017 at 05:56 AM. Reason: More info |
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#12 | |
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Location: East Coast USA Join Date: Feb 2008
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#13 | |
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Location: Cambridge Join Date: Sep 2010
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Basically significant amount of the clusters on the run contained shorter templates, and once the end of these is reached (140-160 bp), it wrecks RTA dephasing calculations. since templates in the 150-200 bp cluster very efficiently compared to 500-800 bp ones, it takes only 3-5% of the shorter contaminant to wreck Q scores in the run. To minimize it avoid repetitive freeze thaw cycles of the Illumina adapters (they can lose T tails and self ligate) and make sure no nucleases contamination is present during the ligation. |
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#14 | |
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Location: CT Join Date: Apr 2015
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The suggestion that there may be a primer diamer issue is reasonable, but you also may need to up your density a bit.
__________________
Microbial ecologist, running a sequencing core. I have lots of strong opinions on how to survey communities, pretty sure some are even correct. |
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#15 | |
Jafar Jabbari
Location: Melbourne Join Date: Jan 2013
Posts: 1,238
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#16 |
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Location: California Join Date: Jul 2014
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We did a 2x300 run for a TCR library recently. Passed spec (77.5% Q30 @ 939k with 15% PhiX), but clear tailing towards the ends of both R1 and R2 as well.
I could see error rates approaching 5% being problematic for many if not most applications. We'll be sticking with 2x250 or 2x150 chemistry for the time being, unless specifically requested by a client. |
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#17 |
Jafar Jabbari
Location: Melbourne Join Date: Jan 2013
Posts: 1,238
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To my knowledge error rate is not included in Illumina specifications. Q scores drop after cycle 250 is a known characteristic of the chemistry and for some applications it will not be detrimental.
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#18 |
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Location: UK Join Date: Jan 2010
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So.. no this issue is not resolved. I have an email from Illumina today which I will summarise.
The issue is that there is a byproduct in their manufacturing process of fluorescent nucleotides. This byproduct results in NON-CLEAVABLE NTPs - so they limit strand growth. Obviously this has limited effects on the number of clusters per cycle, but does become more acute on 600 cycle kits as the problem 'builds'. You get a lower cluster density, and lower Q30 and higher error rates on the later cycles. Illumina can now *detect* this byproduct and know what levels impact performance, which sounds to me like there might be batch to batch variation, and have put in place measures to screen for it, therefore they are still expecting improvements 'in the near future' as newer material hits the manufacture pipeline. I am also told there will be a new announcement soon, with new timelines for resolution. |
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#19 |
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Location: america Join Date: Apr 2015
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I've have also heard that the problem wasn't resolved, but never had details as to the cause.
Thanks! |
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#20 |
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Location: Scotland Join Date: Jan 2013
Posts: 8
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Many thanks Bukowski, that's the first logical explanation I have heard. Looking forward to any announcements from Illumina going forward.
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