Figure 5
From: Computational method for reducing variance with Affymetrix microarrays
Volcano plot Statistical significance by t-tests [-log(P)] vs. expression ratio (mean old / mean young) for 4629 targets that passed the presence / absence filter. Note log2 scale on horizontal axis. Vertical lines represent 2-fold difference between young and old. Upper horizontal line represents P = 0.001. Lower horizontal line represents P = 0.01.