[BioC] two color arrays normalization
Naomi Altman
naomi at stat.psu.edu
Wed Feb 18 01:50:15 CET 2009
Hi Giusy,
Move the minus signs from the first design matrix to the 2nd and I
think it will work fine.
--Naomi
At 06:07 PM 2/17/2009, Giusy Della Gatta wrote:
>Hi Naomi,
>
>I performed the analysis of my micorarrays,but still I don't manage
>to revert the channels!
>My experiment consisted into infect cells with an adenovirus: an emty one
>and an adenovirus expressing for a specific protein. Then I
>treated the same cells with a specific drug or simply with the vehicle (DMSO).
>I have 6 microarrays: 3 controls DMSO0-treated and 3 samples drug-treated.
>In each microarray the green channel is expressing the levels of
>infected and treated
>cells while the red channel are not infected cells. For all the experiments
>I have the same RED CHANNEL reference.
>I composed the target file as follows:
>
>Filename Cy3 Cy5
>Control_1b.txt ctrl ref
>Control_2b.txt ctrl ref
>Control_3b.txt ctrl ref
>dexa_dbz_lt_1.txt treat ref
>dexa_dbz_lt_2.txt treat ref
>dexa_dbz_lt_3.txt treat ref
>
>and the I used the following script:
>
> >targets=readTargets("target_frame_ltbarc_pgedit.giusy")
> >RG<-read.maimages(targets$FileName, source="agilent", ext="txt")
> >MA<-MA.RG(RG, bc.method="normexp")
> >MA<-normalizeWithinArrays(RG, method="loess")
> >design <- modelMatrix(targets, ref="ref")
> > design
> ctrl treat
>[1,] -1 0
>[2,] -1 0
>[3,] -1 0
>[4,] 0 -1
>[5,] 0 -1
>[6,] 0 -1
> >fit<-lmFit(MA,design)
> >cont.matrix<-cbind("ctrl-ref"=c(1,0), "treat-ref"=c(0,1))
> >cont.matrix
> ctrl-ref treat-ref
>[1,] 1 0
>[2,] 0 1
>
> >fit2<-contrasts.fit(fit, cont.matrix)
> >d1 <- ebayes(fit2)
> >toptable(fit2,adjust="fdr")
>
>I don't know if I am still omitting
>something, because I have the positive
>controls of this experiment that
>are going exactly in the opposite way!!
>
>May you can help me?
>
>Thank you in advance!
>Giusy
>
>
>-----Original Message-----
>From: Naomi Altman [mailto:naomi at stat.psu.edu]
>Sent: Mon 2/9/2009 9:56 PM
>To: Giusy Della Gatta; bioconductor at stat.math.ethz.ch
>Subject: Re: [BioC] two color arrays normalization
>
>If there is no dye-swap, then what do you mean by "swapping of the colors"?
>
>--Naomi
>
>At 07:56 PM 2/9/2009, Giusy Della Gatta wrote:
>
> >Hi everybody,
> >
> >I am analyzing two color Agilent microarrays
> >by using LIMMA package.
> >In my specific case the red channel is representing
> >"the reference" while the green channel is "the treatment".
> >Is it enough to use the Target File composition to specify the name
> >of the samples
> >and their corrispondet channels? Or I have to use other specific commands
> >to specify the "swapping" of the colors?
> >
> >Thank you in advance!
> >Regards
> >Giusy
> >
> >_______________________________________________
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>
>Naomi S. Altman 814-865-3791 (voice)
>Associate Professor
>Dept. of Statistics 814-863-7114 (fax)
>Penn State University 814-865-1348 (Statistics)
>University Park, PA 16802-2111
Naomi S. Altman 814-865-3791 (voice)
Associate Professor
Dept. of Statistics 814-863-7114 (fax)
Penn State University 814-865-1348 (Statistics)
University Park, PA 16802-2111
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