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  • Suspected bad batch of XLR70 sequencing reagents!!!!!

    Beware, as of 19th July 2012 Roche have said that there MAY be an issue with XLR70 sequencing reagent Lot. number 93859420.

    They can't say at present what the issue may be or what reagent, only a suspicion based on two sites and won't be pressed on the last 6 months at least of inconsistent and/or sub-standard runs, or the previous similar problems in 2010 when it turned out to be PicoTiter plates.

    Considering the machines were serviced, and we ran their own 454 controls which failed the only other option I can foresee could be possible Flx+ upgrade issues, as we've experienced issues since ours were. Although we saw similar issue with the standard Flx machines as well.

    It may of course possibly be (according to Roche):

    1. Our tissue lyser is noisy. It was new last year and the noise level is the same as it's always been, although we have moved labs and the bench it sits on now may reverberate more so we have used a rubber mat to eliminate this now.
    2. We don't use Eppendorf pcr plates and caps, which whilst they may be the only ones Roche "accredit" (they haven't showed me the test results pertaining to the tests I presume they carried out to ascertain this, but I have asked), we've only ever used Star lab plates and adhesive seals. There hasn't been a technical bulletin released even though they have been aware of what plates we have been using for 5 years. Although they will tell you that some customers have been "amazed" by the difference (a bit like when you change soap powder to a leading alternative I presume....). I would have thought that if this was the case it would have become a technical bulletin.
    3. Gently drawing up 200ul emulsion with an Eppendorf repeater pipette (recommended and still ok to use you'll be happy to know) and gently dispelling again to remove the air bubble at the top of the tip (as this compresses differently than the emulsion and will cause leaking/drops) can break the emulsion microreactor, yet subsequent expelling of said emulsion in 100ul aliquots using the trigger at a far greater speed doesn't have an effect.

    Phew, that's a relief and very satisfactory.
    Last edited by ChristianBourne; 07-20-2012, 01:49 AM.

  • #2
    I've edited my previous post as the stress that this scenario has caused me may have affected my judgement on what I wrote. I have removed any personal feelings and just stated the facts.

    Apart from the 'satisfactory' part, obvs....

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    • #3
      What kinda results are you getting?

      We never used Eppendorf plates but our FAS left some in the lab and we were gonna do a comparison soon.

      Comment


      • #4
        What kind of results for what, sorry?

        Comment


        • #5
          Sequencing results. Short reads, small number of reads, small number of passed filter wells...that kinda result that make you (and/or Roche) think there is a problem with that lot of reagents.

          Comment


          • #6
            Hmm. We've used those reagents (XLR70 93859420) four times, and had three successful runs, one bad run. Roche couldn't find a reason (they said) but did offer today to replace the reagents for that run. I'm just back from Mat Leave, I left in December not knowing what was going on with any of my samples- all giving either really high or really low enrichment. That turned out to be a problem with the bead recovery reagents. The failed sequencing run with the above reagents was done by the person who filled in for me on leave; when I used the reagents they worked and I was delighted that everything looked ok. I put on a second run Monday though and while I got high no.s of reads, the quality is really poor-averaging about Q20 instead of Q40. This was with lot 93871120- anyone any problems with that one? Or ever have that happen to them? It's never happened to us before- "normally" if a run is bad it's because of low no.s, not low quality.

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            • #7
              have used those reagents 5 times, one failed run (low numbers). Roche are replacing kits, I was surprised because I suspected failure was actually our fault as enrichment was very high....

              Comment

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