Effect of local background intensities in the normalization of cDNA microarray data with a skewed expression profiles.

摘要: Normalization of the data cDNA microarray is an obligatory step during experiments due to relatively frequent non-specific errors. Generally, normalization based on null hypothesis and variance model. In Yang's model (Yang et al., 2001), at least two types noises are included. The one additive noise other multiplicative noise. Usually, background considered as signal variation between pixels representative this study, relation (spot intensity minus intensity) was observed influence a factor investigated. Although has not been affecting normalization, it could improve accuracy when carried out considering signal/background ratio. dependent decreased number genes whose expression levels were changed significantly make their distribution more consistent through whole range intensities. printing pin also regarding It improved spots in Cy3-Cy5 scatter plot, but its effect slight. These studies suggest that there some influences signals local backgrounds they must be for data.