[BioC] how to separate probe numbers from AffyIDs?

[Jenny Drnevich]

Hello,

I've been using Bioconductor to do the background correction and 
normalization of my data, but I want to use the probe values themselves 
instead of a summary value for my statistical analyses. I am able to export 
the matrix of pm values, but the first column lists the AffyID and probe 
number together (e.g., 100_g_at1, 100_g_at2, 100_g_at3, etc.). Is there an 
easy way to separate these? I need two columns: one with just the AffyID 
(100_g_at) and one with the probe number (1, 2, 3, etc.).  I don't need 
these two columns in the pm matrix I export, because I can combine the two 
in SAS.

Thanks in advance,
Jenny

Jenny Drnevich, Ph.D.
Department of Animal Biology
515 Morrill Hall
505 S Goodwin Ave
Urbana, IL 61801
USA

ph: 217-244-6826
fax: 217-244-4565
e-mail: drnevich at uiuc.edu