Profile variability over 12 replicate aCGH datasets. Noise values (rp68 and dLRs) over 12 replicate samples when using six different normalization methods are shown. Global median (green), qspline.normalize (black), R Lowess (yellow), popLowess (red), marray (purple) and aCGH.Spline (blue). (A, C) The 68th percentile (rp68) over all 12 replicate samples (A), over six medium-quality samples (C). (B, D) The dLRs over all 12 replicate samples (B), over six medium-quality samples (D).