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Thread | Thread Starter | Forum | Replies | Last Post |
Introducing Helicos tSMS™ Sequencing Services from Helicos | Helicos BioSciences | Vendor Forum | 1 | 05-31-2012 06:49 AM |
PubMed: Profiling of Short RNAs Using Helicos Single-Molecule Sequencing. | Newsbot! | Literature Watch | 0 | 12-07-2011 04:10 AM |
PubMed: Helicos single-molecule sequencing of bacterial genomes. | Newsbot! | Literature Watch | 0 | 03-25-2011 03:00 AM |
Helicos sequencing machine data & format required | balamudiam | Helicos / Direct Genomics | 4 | 10-27-2009 09:28 PM |
Helicos sequencing: Single-Molecule DNA Sequencing of a Viral Genome | eldfors | Literature Watch | 1 | 04-04-2008 09:19 AM |
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#1 |
Member
Location: Hyderabad, India Join Date: Apr 2010
Posts: 66
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Hello Everyone,
I was wondering if anyone has any experience in Helicos sequencing. I saw the technology on its website, and it looked pretty robust. I was wondering what were its pros and cons compared to SoliD and Illumina and it was something one would want to invest in. Thanks Abhijit |
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#2 |
Senior Member
Location: USA Join Date: Apr 2009
Posts: 482
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Dana Farber has a Helicos. Contact Paul Morrison there.
http://mbcf.dfci.harvard.edu/docs/QA...ulMorrison.pdf |
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#3 |
--Site Admin--
Location: SF Bay Area, CA, USA Join Date: Oct 2007
Posts: 1,358
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Hey this belongs in...the Helicos Forum!
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#4 |
Junior Member
Location: Boston Join Date: Jan 2009
Posts: 8
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As of this week we have completed over 1,500 ChIP-Seq samples on the Helicos. A few nanograms, no library creation, just a little poly A tailing and zoom, 9-14 million reads on 46 samples every 14 days (we like to relax before we fill it up again.).
Just don't ask me why they just got delisted on NASDAQ and are trading at 22 cents. I have no idea. ;-( Keith Robison spells it out pretty well in the other thread. Their marketing should have been something like "It's all about the message" and focused on ChIP-Seq, RNA-Seq, DGE and all of the above from paraffin, nanogram amounts, no amplification, no bias. They should have never chased after the human genome. Wrong tool for the job. -Paul Morrison Last edited by polytoo; 11-21-2010 at 10:06 AM. Reason: clarity pointing out the demise thread |
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#5 |
Senior Member
Location: Sweden Join Date: Mar 2008
Posts: 324
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Paul,
do you know if there is any published or publicly available ChIP-seq dataset from independent groups? |
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#6 | |
Junior Member
Location: Boston Join Date: Jan 2009
Posts: 8
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If a request came into my lab specifically for ChIP-Seq results I could pass the request on to labs that are close to publishing. One also might be able to get a handle on the right folks if you did a search on "new epigenetics center" and my Institute. |
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#7 | |
Member
Location: Ann Arbor, MI Join Date: Oct 2008
Posts: 57
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I have experience with Helicos mRNA-Seq (having just submitted a paper using the technology). |
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#8 |
Member
Location: USA Join Date: Aug 2010
Posts: 23
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I think Paul knows NASDAQ rules. I guess what he really meant is he doesn't know why Helicos' marketing team didn't do a good job. After all, the technology itself is good enough for some applications.
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#9 |
Senior Member
Location: USA Join Date: Apr 2009
Posts: 482
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I asked a PacBio rep why he thought their SMS will succeed when Helicos failed. He said because their instrument will work.
This may be history repeating itself. Initially people were excited about Dupont's 1st gen sequencer (which didn't work) and then ABI pulled it off successfully. |
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#10 | ||
Junior Member
Location: Boston Join Date: Jan 2009
Posts: 8
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#11 | |
Member
Location: Ann Arbor, MI Join Date: Oct 2008
Posts: 57
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Last edited by Lee Sam; 11-30-2010 at 03:01 PM. |
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#12 |
Junior Member
Location: Melbourne Join Date: May 2012
Posts: 5
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Any updates from any of the users who were/are still working on the Heliscope?
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#13 |
Member
Location: Bielefeld Join Date: Jul 2012
Posts: 24
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Hey everybody,
good to have some people already having some experience with Helicos. In our Lab we are working on an RNA binding protein and try to figure out putative target RNAs. Therefore we did RIPs and subsequently sequenced them with Helicos. But we have pretty low number of aligned reads (up to 21 %). We suppose this is due to the treatment of the samples with formaldehye. Doe anyone of you has experienced similar problems or has an alternative solution? |
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#14 |
Junior Member
Location: Melbourne Join Date: May 2012
Posts: 5
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Dolphin22 curious what lab you work in? Thank you.
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#15 |
Junior Member
Location: USA Join Date: Jan 2012
Posts: 8
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Dolphin22-
Your low aligned yield rate could be caused by many things but you can frequently diagnose some of the problems by looking at the sequence of what doesn't align. If they are very rich in either As or Ts, it was probably a sequencing problem. If short on Gs, it probably means the formaldehyde killed the Cs so you can't see the Gs. If an excess of CTAGs or portions thereof (standard Helicos base order of addition), you didn't filter properly. You may be able to sort out other issues by looking for common features of non-aligning sequences. For example, do they align to other species or does the same sequence keep appearing? S |
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#16 |
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Location: Alaska Join Date: Jan 2012
Posts: 49
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This horse deader than dead when ILMN's lawyer team destroyed the community college kid who worked for free this week...
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#17 |
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Location: Bielefeld Join Date: Jul 2012
Posts: 24
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@ singlemoleculer
Thanks for your advices. I checked my sequences but I am not sure about some points: What does very rich of A's and T's mean? Do you have a percentage? The same with the low number of G's. Of course I find CTAG's but where is the limit? I also find many sequences with long stretches of polyA's polyT's? Is this also an indicator for bad sequencing? |
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#18 |
Junior Member
Location: USA Join Date: Jan 2012
Posts: 8
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The standard Helicos filtering software gets rid of these artifacts automatically. If you don't have access to the software, you can do manual filtering. Very rich in AT means A+T>90%. These are usually caused by problems in sample preparation. Any such sequences should be discarded unless you are working with a very AT-rich set of sequences like Plasmodium in which case you have to adjust the cutoff. For CTAG, you should look at the dimer frequencies. If CT+TA+AG+GC>70%, you should also discard. These sequences are usually caused when 2 DNAs are too close on the flow cell and the signals overlap. The filtering software actually has a more complex algorithm but this is good enough for most purposes.
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#19 |
Member
Location: Bielefeld Join Date: Jul 2012
Posts: 24
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Thanks for your reply.
I did use the Helipshere software for the analyis so the artifacts should be removed automatically. But I will check the nucleotide distribution of my unaligned sequences allos manually. |
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