Figure 2
From: Quadratic variance models for adaptively preprocessing SELDI-TOF mass spectrometry data
SELDI detector intensity response curves. For repeated experiments under homogeneous machine settings, the variance in intensities observed is shown to be quadratic in the mean intensity observed. Thus, peaks occurring in areas of the spectrum affected near the baseline will be more noisy and more difficult to detect. Most algorithms for preprocessing SELDI data assume constant variance, independent of signal intensity. The detector response curve is shown to be dependent on machine settings, as it is different for BUFFER1 and BUFFER2.