I have RNA expression data for 20 control and 20 matched treatment samples. I need to plot z-score change for a gene signature between control and treatment for all the 20.
This is what I think to do:
- Log2 of the expression values
- Calculate z-scores separately for all control
- In the same way calculate z scores for all treatment samples
- For a gene subtract z-score of treatment from z-score of control to get the change
- Plot the z-score change per sample for a gene
Is it ok to calculate z-score separately for control send treatment or should I calculate the z-score together for them? Please let me know the correct way to handle this.