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 In this tutorial, the file name (e.g., Down Syndrome-Astrocyte-748-Male-1-U133A.CEL) contains the information about a sample and is separated by hyphens (-). Choosing to split the file name by delimiters will separate the categories into different columns as shown (Figure 8).

• In the Sample Information panel, specify the column labels (Labels 1-4) as Type, Tissue, Subject, and Gender, set each as categorical, and set the other columns as skip (Figure 8). Select OK
  
  

• A dialog window asking if you would like to save the spreadsheet with the new sample attribute will appear. Select Yes
• Make column 5. (Subject) random by right-clicking on the column header and selecting Properties from the pop-up menu (Figure 9). 
  
  

• Select the Random Effect check box from the Properties dialog (Figure 10) then select OK. 
  
  

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