Analysis of differentially methylated loci in humans and mice typically includes exclusion of the probes on X and Y chromosomes because of the difficulties caused by the inactivation of one X chromosome in female samples. To filter out probes from the X and Y chromosomes, we first need to annotate the ANOVA spreadsheet with chromosome locations.

Now, we can filter probes by chromosome location.

For categorical columns, the interactive filter displays each category of the selected column as a colored bar. For 4. CHR, each bar represents a chromosome with the height of bar representing the number of probes from that chromosome in the selected spreadsheet. To filter out a category, left-click on its bar. Right clicking on a bar will include only the selected category. A pop up balloon will show the category label as you mouse over each bar. 

The yellow and black bar on the right-hand side of the spreadsheet panel shows the fraction of excluded cells in black and included cells in yellow. Right-clicking this bar brings up an option to clear the filter. 

Now that we have filtered out probes on the X and Y chromosomes, we will create a spreadsheet containing only probes on the autosomes. 

It is best practice to occasionally save the project you are working on. Let's take the opportunity to do this now. 

Saving the project saves the identity and child-parent relationships of all spreadsheets displayed in the spreadsheet tree. This allows us to open all relevant spreadsheets for our analysis by selecting the project file.