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Design Matrix For Pre-Subtracted Arrays

I am using limma to look at a GSE microarray (GSE10918 to be specific). I am trying to figure out which design matrix to use before fitting the linear model and am having a hard time figuring it out. It seems from the phenoData, the GSM's are in this format (so they are already subtracted and log2 transformed):

gene1 - control
gene1 - control
gene1 - control
gene2 - control
gene2 - control
gene2 - control

What I want is to find the effects of gene1 and gene2 separately. I am wondering what the best design matrix is for this.

microarray bioconductor limma

Would do please explain it in more details? are you going to transform the raw dataset of GSE for R package limma?

1 answer

You could read the raw data (the GPR files) to obtain separate values for the Cy3 and Cy5 channel.

However the experiment has a common reference design without dye swaps. Even after dye normalization you will not be able to distinguish dye effects from biological differences between renilla and the two genes studied.

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