> For the complete documentation index, see [llms.txt](https://knowledge.illumina.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://knowledge.illumina.com/microarray/non-human-methylation/microarray-non-human-methylation-troubleshooting-list/000006306.md).
# How to obtain Unmethylated and Methylated signal in GenomeStudio for each CpG in the Infinium MethylationEPIC Array
For Illumina Methylation arrays, the Beta value is used as a quantitative measure of DNA methylation at a given CpG site. It represents the proportion of methylated signal relative to the total signal intensity and is calculated using the following formula:
**Figure 1.** Formula for calculating the Beta value.
where:
* Signal A corresponds to the unmethylated intensity value, and
* Signal B corresponds to the methylated intensity value.
The constant value of 100 is included to stabilize Beta values, particularly at low signal intensities.
To obtain the Signal\_A (Unmethylated) and Signal\_B (Methylated) values in GenomeStudio v2011.1, users must access these data within the Methylation Module.
The following steps outline how to view and export these signal intensities for downstream analysis.
1. Under the Sample Methylation Profile table, select the "Column Chooser" icon
**Figure 2.** Column Chooser icon in the Sample Methylation Profile table.
2. The "Column Chooser" window pops up. Under Hidden Subcolumns on the right side, highlight "Signal\_A" and "Signal\_B". Click the "<=Show" button.
**Figure 3.** Selection of Signal\_A and Signal\_B subcolumns within the Sample Methylation Profile Column Chooser.
3. Signal\_A and Signal\_B appear in the Displayed Subcolumns.
**Figure 4.** Addition of Signal\_A and Signal\_B to the Displayed Subcolumns section in the Column Chooser.
4. The Signal\_A and Signal\_B columns appear as subcolumns under each sample, with corresponding values for each cg probe. The total intensity is calculated as:
Intensity = Signal\_A + Signal\_B.
**Figure 5.** Display of Signal A and Signal B columns in the Sample Methylation Profile table after column customization.
**Additional references:**
* [GenomeStudio Methylation Module v1.8 User Guide](https://support.illumina.com/downloads/genomestudio-2011-1-user-guides.html)
* Support Webinar: [Infinium Methylation - Intro to GenomeStudio and BeadArray Controls Reporter Support Webinar Video](https://github.com/illumina-swi/illumina-knowledge/tree/master/articles/Knowledge/Infinium-Methylation-Introduction-to-GenomeStudio-analysis-and-BeadArray-Controls-Reporter-Support-Webinar-Video/README.md)
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| *For any feedback or questions regarding this article (Illumina Knowledge Article #6306), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000008062%20-%20Microarray%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |
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