All .idat files in the folder will be selected by default (Figure 5).

The following dialog (Figure 7) deals with the manifest file, i.e. probe annotation file. If a manifest file is not present locally, it will be downloaded in the Microarray libraries directory automatically. The download will take place in the background, with no particular message on the screen and it may take a few minutes, depending on the internet connection. In the future, you may want to reanalyze a data set using the same version of the manifest file used during the initial analysis, rather than downloading an up-to-date version. To facilitate this, the Manual specify option in the Manifest File section allows you to specify a specific version. For this tutorial, we will use the latest available manifest file.

By default the output file destination is set to the file containing your .idat files and the name matches the file folder name. The name and location of the output file can be changed using the Output File panel. 

 In the Algorithm tab of the Advanced Import Options dialog (Figure 8), there are five options available. Select the () next to each method for details. We recommend using the default options; however, advanced users can select their preferred normalization method. If you want to import probe intensity, raw probe intensity, probe signals, raw probe signals, or anti-log probe intensity values, they can be added to the data import using the Outputs tab of the Advanced Import Options dialog. Probe intensities and raw probe intensities can be used for advanced troubleshooting purposes and antilog probe intensities can be used for copy number detection. For this tutorial, we do not need to import any of these values.

 

The imported and normalized data will appear as a spreadsheet 1 (Differential Methylation Analysis) (Figure 9)