We can use a tab-delimited text file to add sample attributes. The text file should have samples on rows and attributes on columns with the first column containing the sample IDs. 

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Attributes describe samples. Examples of sample attributes include treatment group, age, sex, and time point. Attributes can be added individually in the Metadata tab or in bulk using a text file. In this tutorial, we will add one attribute, 5-AZA Dose, manually.

• Click the Metadata tab
• Click Manage under Sample attributes (Figure 1)
  
  

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• Click Add new attribute (Figure 2)
  
  

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• To configure a new attribute, at Name, type in 5-AZA Dose as the name of the attribute
• Click Add to add 5-AZA Dose as a categorical, project-specific attribute (Figure 3)

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• Select Import
  

The treatment attribute will be added as a column next to the sample name (Figure 4)

Configuring a new attribute AnchorName Configuring attribute

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• Name the first New category 0uM
• Click the green plus icon to add category (Figure 4)
• Repeat for two additional categories, 5uM and 10uM (Figure 5)
  
  

• Click Back to metadata tab 

The data table now includes an Attribute column for 5-AZA Dose (Figure 6). Next, we need to assign samples attribute categories for 5-AZA Dose.

• Select Assign values

The option to edit the 5-AZA Dose field for each sample will appear as a drop-down menu (Figure 7).

• Select the 5-AZA Dose text box for a sample to bring up a drop-down menu with the 5-AZA Dose attribute categories (0uM, 5uM, 10uM)
• Use the drop-down menus to add a treatment group for each sample

The first three samples (SRR592573-5) should be 0uM, the next three samples (SRR592576-8) should be 5uM, and the final three samples (SRR592579-81) should be 10uM (Figure 8).

• Click Apply changes
  
  

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The data table will now show each a 5-AZA Dose attribute for each sample. 

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