On Fri, Mar 28, 2008 at 9:41 AM, Sergii Ivakhno <sergii.ivakhno at="" cancer.org.uk=""> wrote: > Hi Sean, > Thanks for your advice (!) and sorry for the direct enquiry. Neither of > the chromosomes are > represented on the array. Do you know where the problem can be as I am > not involved in > the actual data generation - should I look for updated version of > Agilent annotation for bioconductor? Sergii, You will need to get in touch with the people who generated the data. >From them, you will need to get the specific information about the array design. If in doubt, you or they can contact Agilent with the barcodes from the arrays and try to get details from Agilent, but I would definitely start locally with your laboratory collaborators. The problem you are having does not seem to be related to bioconductor and there is no bioconductor annotation involved when using snapCGH. In fact, it sounds like bioconductor is working just fine. You will need to track down the problem from the laboratory/data generation end. Hope that helps, Sean > -----Original Message----- > From: seandavi at gmail.com [mailto:seandavi at gmail.com] On Behalf Of Sean > Davis > Sent: 26 March 2008 16:06 > To: Sergii Ivakhno > Cc: bioconductor at stat.math.ethz.ch > Subject: Re: [BioC] problem with analyzing human 244k agilent array with > snapCGH > > On Wed, Mar 26, 2008 at 11:45 AM, Sergii Ivakhno > <sergii.ivakhno at="" cancer.org.uk=""> wrote: > > Hello, > > I'm using the snapCGH package to analyse human 244k agilent CGH > arrays. > > targets <- readTargets ("targets.txt") > > RG1 <-read.maimages (targets$File_names, source="agilent") > > RG2 <- readPositionalInfo (RG1,source="agilent") > > > > Unfortunately, when I want to extract chromosome information is > > appears that chromosomes 20,21 and 22 are missing from the RG2 > > obgect > > table(RG2$genes$Chr) > > 2 3 4 5 6 7 8 9 10 11 12 13 > > 16394 16856 13133 13642 13993 14135 13618 11524 12045 11833 12658 > > 10343 > > 10644 > > 14 15 16 17 18 19 23 24 > > 10687 9327 9041 9013 8058 6391 12085 599 > > > > The same results are obtained when directly accessing RG1 object. > > Hi, Sergii. > > It looks like you are missing chromosome 1, also? I quickly added the > numbers you have given here and come up with 236,000+ probes. That is > pretty close to the maximum number of usable probes on a 244k array. > Have you looked at the .txt files to see if chr20, chr21, chr22, or > chr1 are represented on your array? > > Sean >