[BioC] Missing probesets
Robert Gentleman
rgentlem at fhcrc.org
Mon May 2 20:10:54 CEST 2005
On May 2, 2005, at 12:16 AM, Malick.PAYE at eu.biomerieux.com wrote:
>
>
> Hello all,
>
> I installed Bioconductor, the affy package as well as the makecdfenv
> package.
> I have some problems with package makecdfenv (make.cdf.package
> function).
>
> I'm working with a custom chip, then I tried to create a CDF package
> using
> my CDF file, when creating and installing the package everything seems
> to
> be ok but when i read my cel files I realise that about 20% of my
> probesets are missing.
>
> While trying to track the bug it seems that the missing probesets are
> those whose probes are completely/partially included in another
> probeset ?
>
Hi,
I am not sure I understand what you are saying here. Are you saying
that some probes on your chip map to multiple mRNA's? That does seem a
bit peculiar and it will not be precisely clear how to analyze such
data. I suspect that some form of very large EM iteration will be
needed, but I would not expect anything to do it correctly off of the
shelf.
If this supposition is correct you now need to deal explicitly with
cross-hybridization - how much of the signal at each such probe do you
attribute to the *different* underlying mRNA species. This is doable,
provided there is no complete confounding - or stated differently
provided each mRNA species has at least one probe that is unique to it
[probably - there are sure to be more specific conditions since this is
going to become a large optimization problem] - but it is not simple to
do.
Duplicating the probes, to give the appearance of every gene having a
complete probe set will bias your results [directions unknown] and
probably should not be used - unless you have no other choices.
Best wishes,
Robert
> So I suppose that the implementation of this package prevents the
> inclusion of a probeset in another ?
>
> My question : what can I do to reanalyse my data with the entire
> probesets.
>
> I'm not familiar with C language so I can't have a look at the source
> code.
>
> PS : I'm using R version 2.0.1, affy version 1.5.8-1 and Makecdfenv :
> version: 1.4.8
>
> If someone met this kind of problem. ..
>
> Any help would be greatly appreciate.
>
> Malick,
>
> AVIS : Ce courrier et ses pieces jointes sont destines a leur seul
> destinataire et peut contenir des informations confidentielles
> appartenant a bioMerieux. Si vous n'etes pas destinataire, vous etes
> informe que toute lecture, divulgation, ou reproduction de ce message
> et des pieces jointe est strictement interdite. Si vous avez recu ce
> message par erreur merci d'en prevenir l'expediteur et de le detruire,
> ainsi que ses pieces jointes.
>
> NOTICE: This message and attachments are intended only for the use of
> their addressee and may contain confidential information belonging to
> bioMerieux. If you are not the intended recipient, you are hereby
> notified that any reading, dissemination, distribution, or copying of
> this message, or any attachment, is strictly prohibited. If you have
> received this message in error, please notify the original sender
> immediately and delete this message, along with any attachments.
> [[alternative HTML version deleted]]
>
> _______________________________________________
> Bioconductor mailing list
> Bioconductor at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/bioconductor
>
>
+-----------------------------------------------------------------------
----------------+
| Robert Gentleman phone: (206) 667-7700
|
| Head, Program in Computational Biology fax: (206) 667-1319 |
| Division of Public Health Sciences office: M2-B865
|
| Fred Hutchinson Cancer Research Center
|
| email: rgentlem at fhcrc.org
|
+-----------------------------------------------------------------------
----------------+
+-----------------------------------------------------------------------
----------------+
| Robert Gentleman phone: (206) 667-7700
|
| Head, Program in Computational Biology fax: (206) 667-1319 |
| Division of Public Health Sciences office: M2-B865
|
| Fred Hutchinson Cancer Research Center
|
| email: rgentlem at fhcrc.org
|
+-----------------------------------------------------------------------
----------------+
More information about the Bioconductor
mailing list