Using read.maimages() with Imagene output files.
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@luke-whitaker-408
Last seen 10.1 years ago
I am attempting to analyse some microarray data that has been scanned using a program called Imagene and I would like to try and use limma for the analysis. I was wondering if it might be possible to use read.maimages() to read these data into R. It appears to me that read.maimages() expects both the red and green signals to be present in a single file. Imagene produces separate files for the red and green signals. Does anyone out there have any suggestions how to proceed ? Thanks in advance, Luke Whitaker Inpharmatica
Microarray limma Microarray limma • 1.1k views
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@gordon-smyth
Last seen 3 hours ago
WEHI, Melbourne, Australia
Dear Luke, At 01:31 AM 14/08/2003, Luke Whitaker wrote: >I am attempting to analyse some microarray data that has been >scanned using a program called Imagene and I would like to try and >use limma for the analysis. I was wondering if it might be possible >to use read.maimages() to read these data into R. > >It appears to me that read.maimages() expects both the red and green >signals to be present in a single file. Imagene produces separate files for >the red and green signals. Does anyone out there have any suggestions how >to proceed ? What you say is correct - read.maimages does not support Imagene files, nor does any other function in Bioconductor. If you would be prepared to make available to me some examples of imagene data files, then I will add imagene functionality to read.maimages. Gordon >Thanks in advance, > >Luke Whitaker >Inpharmatica
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@gordon-smyth
Last seen 3 hours ago
WEHI, Melbourne, Australia
Hi Nick, You're closer to me, both geographically and time-zone wise, than Luke is so could you please send me four imagene files, i.e., both channels for two different arrays. Please zip or otherwise compress the files and then email them to me in four separate emails. Also, does your scanner produce a separate gene allocation list specifying which gene corresponds to which spot? At the moment, limma provides direct support only for Genepix allocation lists. Cheers Gordon At 11:35 AM 14/08/2003, Nick Matigian wrote: >Hi Gordon >I have the same problem as Luke. So if he does not send you any ImaGene >files I can. > >Nick Matigian > >Queensland Centre for Schizophrenia Research >www.qcsr.uq.edu.au > >Queensland Institute of Medical Research >www.qimr.edu.au > >nickMa@qimr.edu.au >Telephone: 61 7 3362 0308 >Facsimile: 61 7 3845 3508 >Queensland Institute of Medical Research >Post Office Box Royal Brisbane Hospital >Herston, Queensland, Australia, 4006 > >-----Original Message----- >From: Gordon Smyth [SMTP:smyth@wehi.edu.au] >Sent: Thursday, August 14, 2003 10:25 AM >To: Luke Whitaker >Cc: bioconductor@stat.math.ethz.ch >Subject: Re: [BioC] Using read.maimages() with Imagene output files. > >Dear Luke, > >At 01:31 AM 14/08/2003, Luke Whitaker wrote: > >I am attempting to analyse some microarray data that has been > >scanned using a program called Imagene and I would like to try and > >use limma for the analysis. I was wondering if it might be possible > >to use read.maimages() to read these data into R. > > > >It appears to me that read.maimages() expects both the red and green > >signals to be present in a single file. Imagene produces separate files for > >the red and green signals. Does anyone out there have any suggestions how > >to proceed ? > >What you say is correct - read.maimages does not support Imagene files, nor >does any other function in Bioconductor. > >If you would be prepared to make available to me some examples of imagene >data files, then I will add imagene functionality to read.maimages. > >Gordon > > >Thanks in advance, > > > >Luke Whitaker > >Inpharmatica > >_______________________________________________ >Bioconductor mailing list >Bioconductor@stat.math.ethz.ch >https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor
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@gordon-smyth
Last seen 3 hours ago
WEHI, Melbourne, Australia
OK, try out limma version 1.1.11 which is available from http://bioinf.wehi.edu.au/limma/ I have added "imagene" as a possible value for the argument 'source' for 'read.maimages'. For Imagene data, the argument 'files' should contain a matrix of file names, the first column for the cy3 channel files and the second column for the cy5 channel files. I have made "Signal Mean" the default for foreground and "Background Median" the default for background. Here is a little example: > files [,1] [,2] [1,] "cy3-pt1-cf-t0-7946.txt" "cy5-pt1-cf-t0-7946.txt" [2,] "cy3-pt1-wt-t3-8179.txt" "cy5-pt1-wt-t3-8179.txt" > RG <- read.maimages(files,source="imagene",names=c("slide7946","slide8179")) Read header information Read cy3-pt1-cf-t0-7946.txt Read cy5-pt1-cf-t0-7946.txt Read cy3-pt1-wt-t3-8179.txt Read cy5-pt1-wt-t3-8179.txt > MA <- normalizeWithinArrays(RG) > RG An object of class "RGList" $R slide7946 slide8179 [1,] 471.7000 1310.4737 [2,] 478.9474 1192.4118 [3,] 603.3200 1678.8700 [4,] 698.8986 1658.7586 [5,] 428.0727 589.9016 19195 more rows ... $G slide7946 slide8179 [1,] 543.8400 1021.7600 [2,] 492.4182 1033.5517 [3,] 722.1818 1505.1881 [4,] 696.3235 1454.2424 [5,] 460.9800 588.2407 19195 more rows ... $Rb slide7946 slide8179 [1,] 582.0 1563 [2,] 624.0 1609 [3,] 530.0 1615 [4,] 606.5 1429 [5,] 706.0 1256 19195 more rows ... $Gb slide7946 slide8179 [1,] 598 1337.0 [2,] 643 1271.5 [3,] 730 1663.0 [4,] 741 1348.0 [5,] 714 1067.5 19195 more rows ... $printer $ngrid.r [1] 8 $ngrid.c [1] 4 $nspot.r [1] 25 $nspot.c [1] 24 $genes Field Meta Row Meta Column Row Column Gene ID 1 test 1 1 1 1 R11726: 2 test 1 1 1 2 R11726: 3 test 1 1 1 3 R37412: 4 test 1 1 1 4 R37412: 5 test 1 1 1 5 R11793: 19195 more rows ... You can change the foreground/background if you like, for example: RG <- read.maimages(files,source="imagene",columns=list(f="Signal Mean",b="Background Mean")) Gordon At 07:29 PM 14/08/2003, Luke Whitaker wrote: >Dear Gordon, > >Thank you for your offer. I am enclosing an example of a (truncated) >Imagene file. I have deleted 7869 lines from the "Raw Data" part >of the file partly because the data is confidential but mainly to >make the attachment a more reasonable size - the original file is >4Mbytes. I hope this isn't a problem. If it is, let me know and I >will work something out. > >Note that the Imagene format relies on tabs to separate fields, >and that many of the items can contain spaces. In particular, the >"Raw Data" column headers often contain spaces (eg "Meta Row", >"Meta Column", "Signal Mean", "Background Mean" etc etc) and also, >the "Gene ID" names can contain spaces (eg "(+)Pro25G onG3PDH570 1(60)" >in the example I have given you). > >I believe that as long as the distinction between tabs and spaces >is observed then there is no ambiguity. > >As I said before, there is one file for each dye, and there does >not appear to be any information in the file itself as to which >dye the file is for. We encode the dye in the tiff filename, but >that is not enforced. > >Also, I understand that the columns that are output, and possibly >the actual column names, are to some extent configurable in Imagene, >so it is probably not safe to assume that the file will always >contain exactly those columns with those particular column headers. > >If there is any further information I can give you then please let >me know. I would be very grateful if you could let me know how you >get on. > >Thanks, > >Luke >Inpharmatica > > >On Thu, 14 Aug 2003, Gordon Smyth wrote: > > > Dear Luke, > > > > At 01:31 AM 14/08/2003, Luke Whitaker wrote: > > >I am attempting to analyse some microarray data that has been > > >scanned using a program called Imagene and I would like to try and > > >use limma for the analysis. I was wondering if it might be possible > > >to use read.maimages() to read these data into R. > > > > > >It appears to me that read.maimages() expects both the red and green > > >signals to be present in a single file. Imagene produces separate > files for > > >the red and green signals. Does anyone out there have any suggestions how > > >to proceed ? > > > > What you say is correct - read.maimages does not support Imagene files, > nor > > does any other function in Bioconductor. > > > > If you would be prepared to make available to me some examples of imagene > > data files, then I will add imagene functionality to read.maimages. > > > > Gordon > > > > >Thanks in advance, > > > > > >Luke Whitaker > > >Inpharmatica
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