Skip to main content
Figure 3 | BMC Bioinformatics

Figure 3

From: Statistical monitoring of weak spots for improvement of normalization and ratio estimates in microarrays

Figure 3

Localization of additive noise through an F-test. A. Histogram of gene expressions from a microarray experiment. B. P value distribution showing correlation of additive noise as determined by F test. A window of 20 genes was created to calculate the groups SD and further windows were created by shifting the index of the ordered SD's by one gene. For example: widow 1 contains genes 1–20 and window 2 contains genes 2–21. As the expression level in these windows increases the SDs become correlated and a p-value threshold becomes apparent. C. Close up histogram of low intensity spots used as background. The Gaussian distribution can clearly be seen; furthermore, the right tail cutoff of the Gaussian distribution is at the expression level corresponds to the p value threshold for the ratio calculation in B.

Back to article page